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Fuel Injection Cleaner -- Injector Cleaning

Fuel Injection Cleaner -- Tuneups and Fuel Economy

Fuel injection cleaner, also known as injector cleaner, is a simple trick that can give you a lot of bang for your buck. You pour it in your gas tank when filling up at the gas station, and away it goes. Especially in California, where emissions tests happen often, having a peak performance vehicle is very important. Clean fuel injectors help ensure:

  1. Fuel Economy
  2. Emissions
  3. Peak Engine Performance

If that's something you want as a car owner, consider using a fuel injection cleaner every couple of months.

Fuel injection cleaner, also known as fuel injector cleaner helps clean dirty parts like this.

Fuel injection cleaner, also known as fuel injector cleaner helps clean dirty parts like this.

Dirty Fuel Injectors

When fuel injectors are dirty, they can't deliver the correct spray required for combustion, and as a result, fuel economy and engine performance suffers. This, in the long run, can be costly or can even begin to cause symptoms:

  1. Rough Idle
  2. Misfiring
  3. Poor Fuel Economy

That's why fuel injection cleaner is a must. The reason I recommend fuel injector cleaner is because it's one of those simple things a person can do without having to replace any parts or any under the hood work. Normally in a tuneup, lots of things get replaced, things like spark plugs, distributor caps, belts, and fluids. But with fuel injectors, running an additive through a tank of gas every once in a while will keep them clean and running properly. It's something you can do cheaply and without automotive knowhow. Just follow the instructions on the bottle.

How Fuel Injector Cleaner Works

Over time, all fuel injectors become clogged. This happens because the deposits come from the gasoline itself. Gasoline is a compound mixture of hydrocarbons, and includes waxy, heavy chemicals known as oilfins, which yield a lot of energy when burned. As long as a car is running, the fuel injectors and engine runs efficiently. The clogging occurs when the engine is shut off, and a process known as heat soak occurs. Residue of fuel in the injector nozzles begins to evaporate, and it leaves the oilfins behind, which don't evaporate and some of which don't get washed away, but instead get baked into hard varnish deposits, which ultimately will clog the injectors.

Newer injectors are more resistant than the old ones to this kind of clogging, and additives are added to gasoline to try to dissolve some of these buildups. But cars that make mostly short trips are still especially susceptible to fuel injection clogging, and every injector will ultimately become clogged over time. If the fuel injectors are never cleaned, as the car ages you'll start to notice that your car shakes a bit while idling and eventually it will either stall or misfire, and all the while your fuel economy and engine performance will suffer. I was just in a car the other day that suffered from a very rough idle, and the driver had to keep a little pressure on the gas petal while stopped to keep the car from stalling. Fuel injector cleaner works by stripping away the clogging the builds up over time.

The Best Fuel Injector Cleaner

There are many different kinds of fuel injection cleaners, and the best fuel injection cleaner is one that might surprise you. It's gasoline itself! Cheap gasoline is often lacking in the additives that breakdown clogging and, over the long haul, can cost you more money than it saves. That being said, there are also some very good brands of fuel injection cleaner out there. I like Red Line's fuel system treatment the best. Red Line's Fuel injection cleaner is a total fuel system cleaner and works really well.

Another great way to go is seafoam, which I've written a lot about as well. Seafoam can be added to your gas tank as well as your oil. Check out the link for more info. Some other great injector cleaner is STP injection cleaner. It's reported to have the highest concentration of cleaning agents out of any fuel system cleaner. It's good for really tough clogs, but I still prefer Redline fuel system cleaner for boosting overall fuel economy. The best tip for keeping your injectors clean is to not buy cheap gas, but this is only a preventative measure. My guess is that for people reading this article, it's because your fuel injectors are already partially clogged and are causing problems to your engine performance. If that's the case, then you still have quite a few options. There are many cheap fuel injection cleaners that you can add to your gasoline which will act like drano on a sink pipe and will dissolve many of the clogs in your injectors. One such product is listed to the right. When used semi-regularly (once every few months) it will keep your injectors nice and clean.

But this may not be enough for some engines. Older engines already experiencing heavy problems may need a bigger hand. For this, you may actually need a fuel injection cleaner kit that will allow you to dismantle the fuel injection system and give it a nice clean. However, this is not always possible and some fuel injectors are delicate. Before trying this, I would definitely recommend running a bottle of fuel injection cleaner additive or two through a tank of gas and see if that helps at all. It's cheap and effective.


philip amos on March 29, 2019:

a very useful and informative article. I use Redex cleaner.

Mahmoud Abouzed from Egypt on May 16, 2017:

kenny on June 29, 2016:

I saw that you recommend Techron, but it's quite expensive. Lucas and BK44 are better alternatives I think.

Check here:

abid on December 26, 2014:

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1999 Pathfinder - engine smooth when first started in morning and runs well - but after half hour or so engine misfires and loses power off and on - not consistent.

Dorothy-Ann on November 15, 2014:

Thank you read your advice on using the fuel cleaner! Worked right away while we were driving the car. Like a miracle! Our car runs great now! Thank you!

Kyle McCombs from Providence, RI on October 26, 2013:

BG 44K is the best injector cleaner that just goes in the fuel tank. If you have the equipment, use the BG "Fuel Injection Service" Kit. It works wonders! I talk about it a little bit in my Hub if you want to read about it, I will be doing more write ups also.

steve on August 11, 2013:

aoao 95lexus400 ls i was going down the road it stated skipping bad it didnt run hot so i put in some injector cleaner got in the next day it started smoking white smoke i put new oring on the injectors it still doing the samething you can smell the gas from tailpipe gas be on the third plug on the passenger side ,think its a blown headgasket.

lwes4 on February 14, 2013:

I have a question have a2010 dodge avenger went in for a routine oil change, my car was running fine before i took it in no lights on no check engine light on no nothing get oil change they recommended oil change, transmission fluid and fuel injection clean. got all of that done car was misfiring not getting gas and i got around the corner went back to the place by then the check engine light is flashing and te nattery light pops up never had this problem he said well looks like you alterntor is not working properly well got that replaced, still misfiring while giving gas so they recommended going to another place foiund out they flooed the fuel injector and the spark plugs were jacked but changes the spark plugs but it is still misfirig they are saying that something is wrong when they change the alternator. I am not getting mo gas misfiring and it dies out on me. what do you thing it is?

Phil on September 30, 2012:

I have a 2001 Buick Lasabre Custom 3.8 that starts fine most of

time. 3 or 4 times a week when I turn the key there is no sound & then it will start after 4 or 5 tries. Is it the fuel injector or starter? Keys do not go into the door lock or ignition smoothly. A diagnostic check won't help because it starts fine most of the time. I have had this problem for three months.

Thank you

Kristina Hedley on July 01, 2012:


I'd been having issues with my 1992 Dodge Dakota V8 for a while, especially when I got gas. The truck wouldn't start easily after getting gas, it would take about 3 tries to get it going. I'd have to sit at the gas pump for about 10 minutes before I could get it started.

Anyways, I was talking to several people, had some ideas as to what was wrong with the truck, but this was proven to be wrong yesterday when I wound up going to my mechanic.

While in a parking lot yesterday, the truck refused to start at all. We tried several times, played with the throttle cable, but nothing.

This so called mechanic, who claimed to have several older trucks, he looked at the fuel injectors and stated that the carburetor was bone dry!!!! On a truck that has never had one, and I was told that the other day!

So this bozo dumps fuel into the fuel injectors saying that it was supposed to spew out of the carburetor when I went to start up, but nothing happened.

More fuel was put in to try to get it started before calling a tow truck, big mistake I found out later. When this didn't work, we called for a tow and went to my mechanic.

My mechanic tried to start my truck with no luck either. He told me to try while fiddling around inside. He motioned me out and said that there was no spark in the ignition coil and that he would have to replace it.

When this was done, he told me to start it up. It still wouldn't start. He said to put my foot on the gas and try it again. Heavy plumes of smoke came out of the exhaust pipe and you could smell the fuel burning off.

He told me that this was because of this idiot who insisted that my truck had a carburetor when it didn't.

Last night I went to turn my truck around, and I guess there was still a little fuel in the injectors, and I had to gas it to get it started.

Today, it starts like it used to, properly and right away.

I get lousy gas mileage as it is. I'm not American, so I'm not going to convert measurements, you can if you want. I get about 60 liters of fuel in a tank, and a tank gives me about 250km for city only driving. I had a minivan before that would get me almost 400km to a tank, so this is pretty bleak, even for a v8.

I do buy cheap gas, but even when I don't, my fuel economy is poor, and the performance with my truck is about the same.

I've only seen STP sold in stores here, so I now will try it to see if this will make a difference in time with everything. Now that I know I have fuel injection and not a carburetor, I know not to waste my money on carb cleaner.

Liz on June 09, 2012:

Hi there, I have a 2004 dodge neon and I was told I need to replace the purch canister in my gas tank and its been a few yrs now still running with the old canister and I am wondering would this cause any issues with the performance of my car because there has been times where I would go start my car early in the morning and it feels like it is trying to connect to something but wont start so after the second time of starting the car it would start. Do you think getting a fuel injection cleaner would help with this problem? Thank you! on June 07, 2012:

I have a 1996 Chevrolet K1500 Silverado Pickup 4X4 with 228,000 miles. A couple weeks ago it started to hesitate when pulling hills and when you step into the pedal or passing gear. It seems to idle just fine and no shut off or stall has happened. I changed the sparks plugs and wires. The next day the service engine soon light came on. That same day I put a new fuel filter on. It pulled a code of P0307 #7 Cylinder misfire. Keep in mind service engine soon light never came on till "after" I changed the plugs and wires! Should I try a bottle of fuel injection cleaner or do you think it's a more serious problem? on May 31, 2012:

I bought a 2001 Ford Focus and when you turn on the A/C you get a gas smell in the car. What could that be and is it expensive to fix? on May 31, 2012:

amazing all the different opinions and advice on fuel inj cleaners, i've used most and very few work, for all these advice givers i have some advice, ask your auto dealer what they use to clean injectors in their machines. the info may or may not be easy to get but i is techron, so if the general motors dealers mechanics use techron instead of other chemicals, and have for years, why would you use anything else? bg44k and chevron injector cleaner are the only two i have found that have techron, the bg in just more concentrated.

chall212 on May 16, 2012:

I have a 2003 Chevy Silverado 2500 HD. Recently it has started to stall when I reverse slow (like under 10-15mph) The other day it stalled out on me when i was pulling into a parking spot. Thats the first time going forward it has done that. My husband is gone for business and of course can not help me. I know nothing about vehicles. the battery was dead the other morning when I came out to start it (think this was due to the kids leaving a door opened all night). I got it jump started by a friend and they told me that it was idiling very low, that it wasn't getting enough power and that's why I was having the issue stalling in reverse. When it's in gear and I am drinving, there is absolutely no issues. I am thinking this fuel injector cleaner might sound like a solution or at least something to try. What do you think?

Benji Mester (author) from San Diego, California on May 15, 2012:

Hey Ron, sorry it took me so long to get back to you. It really could be a number of things unfortunately. If you're only lacking a little bit of power at slow speeds, then odds are that one of your systems is a bit clogged, whether it be the MAF sensor, fuel injectors, fuel pump, air filter, etc. It's hard to diagnose a slight lack in power like that. Often, the best thing you can do is to get a general tuneup, where they replace your air filter, clean your MAF sensor, and check the spark plugs. You can dump a bottle of fuel injection cleaner in at the same time if you want also, and just try and kick all the problems at the same time.

Ron on May 10, 2012:

Your article is very informative and well detailed. Today's gasoline has Deposit Control Additives in it(Nitrogen) which helps keep engines cleaner. I use High Octane rated 91 to 93 as I have a 1990 ZR-1 high compression engine which keeps it clean. But recently I have noticed while driving in city at low speeds when giving it gas car starts to jerk back and forth as if not getting enough gas. But on the highway doesn't have a problem. Figure it could be either a fuel problem Fuel Pump) or a spark plug problem. I would appreciate your advice on what I should check first that may be causing the problem. Thank You

Benji Mester (author) from San Diego, California on May 03, 2012:

Hey Kara, sorry again it took so long to get back to you. That's great that Napa has such a great sale. That's super cheap for Seafoam. I love the stuff. Can use it all over the engine compartment. It sounds probably like you're dealing with a clog of some kind. If you're accelerating or going up a hill, there's more strain on your vehicle, meaning that it needs more fuel. So if it starts to run rough at that point, then you're probably dealing with a clog somewhere that isn't getting enough fuel or air to the combustion chamber to meet the demand for power.

If the seafoam doesn't fix the problem, then your clog must be somewhere else. The most common clogs form in your fuel injectors, MAF sensor, fuel filter, air filter, and fuel pump. I've written a couple of articles on how to fix clogs in some of those systems. It's also possible that one or more of your spark plugs is fouled, but that you only notice it when you need extra power. I'd encourage you to read my article on spark plug problems as well. Hope some of this is helpful. Good luck!

Benji Mester (author) from San Diego, California on May 03, 2012:

Hey guys, sorry it took me so long. I've been super busy these days :(

Kevin -- Water can cause symptoms like that, but they shouldn't persist. If you've already changed the injectors and added a bottle of cleaner, it sounds like this has been happening for a little while now. If I were to take a guess, I'd say it sounds more like fouled spark plugs to me. Is there anything in your exhaust, a smoke of some color, or the scent of unburnt fuel?

Kara on April 29, 2012:

Hi Benjimaster. I know you haven't had a chance to answer my question yet. BUt while I'm waiting I'm going to try adding Seafoam to my gas tank. I figure it can't hurt. But I thought I would let you know right now Napa Auto parts, if you order online and pick up at their store a can of Seafoam is about $6.50! So I'm getting 2 of them today! I live in the San Diego area so I don't know if it's just my area or everywhere but I thought you might like to know.

Kara on April 29, 2012:

Hi Benjimaster! I have a 2001 Ford Explorer and for a while whenever we (my husband and I) would fill it with gas it would start to run rough when accelerating on the highway and/ when going up a hill. The check engine light would flash on and off. My husband would step on the gas and the truck would run even more rough but then it would seem to stop and the check engine light would go off. Or it would stop when we went down hill. Then it stoppped doing this for a while and it started doing it last night on our way home while our gas tank was at 1/4 of a tank or less. I won't go into details but in the past 2 weeks due to medical issues and the truck needed a new battery (didn't know you needed to make sure that battery has water in it) we've already spent over $750 and can't afford to take it to a mechanic, but we rely on it for transportation. Could it be possible that all we need is a new fuel filter and possibly the fuel injector cleaner? I thank you in advance and hope to hear from you really soon!

kevin on April 29, 2012:

have a 2004 mg zr 1.4, was having problems starting and once started would tick over very lumpy, changed the fuel injectors and the car started straight away and ticked over spot on, took for a drive(4 miles) then it started ticking over lumpy again, stopped the engine and now wont start again.would water cause this, would water not pass through the injectors, have put in injector cleaner with no effect.

Benji Mester (author) from San Diego, California on April 18, 2012:

Hey James. Yeah, you can definitely add it in fractions. It shouldn't hurt the effectiveness because the ratio will still be the same. I've not heard of people doing that before though, so I'm not positive it'll still be 100% effective to do that way. If your trips are really short and your engine doesn't have time to run at operating temperature for very long, it might be hard for the injection cleaner to break down any serious clogs.

James on April 17, 2012:

Hi, can I put fuel injector cleaner in fractions, not full bottle content? Let's say, I gas up 1/4 of my full tank's volume, then I put 1/4 volume of the fuel injector cleaner?

Will it be alright to fill it in fractions? Will it hurt the effectiveness of the cleaner? Or better to fill in whole bottle's content with fuel tank in full?

The reason I'm asking this is that I do short trips only and don't usually fill my tank full because of the weather here in the Philippines which will quickly evaporate the gasoline.


Benji Mester (author) from San Diego, California on March 17, 2012:

Alan, if you've tried fuel injection cleaner and it didn't help, the your problem is most likely with a dirty MAF sensor or fouled spark plug that's leading to a misfire. In the article above I linked to 2 other articles that I've written about both those subjects. I'd check those out and see what you think.

Benji Mester (author) from San Diego, California on March 17, 2012:

Jeffery, it sounds like they're just going bad. What you're describing has definitely been known to happen. If they're not clogged but are spraying too much, then they either need to be worked on by a mechanic or else just replaced. The spray required is pretty precise, and injectors definitely sometimes go bad like this. If it were me, I'd probably take them out and give them a thorough cleaning before just replacing them outright. If you have too rich of a fuel/air mixture, then it'll definitely cause poor fuel economy and rough idle.

alan on March 16, 2012:

I have a 1997 Honda Accord and it recently started to feel like it's going to die out after I first start driving. It idles a little rough too. After it warms up it's OK. When it acts up, I let my foot off of the gas pedal then tap the pedal lightly a few times to keep it going. I tried a bottle of fuel injector cleaner in the gas tank but it didn't help. Is there something else I can try?

jeffery 07 on March 15, 2012:

i have looked down in it and the injectors are spraying to much fuel do you know what would cause it to do that.

Benji Mester (author) from San Diego, California on March 15, 2012:

Well, it's most likely a system or two clogging up on you. The most common causes are clogged fuel injectors, dirty MAF sensor, dirty air filter, fouled spark plug/plugs, or a clogged fuel filter or pump. Your engine either isn't getting enough fuel or enough oxygen, and so your idle isn't enough to keep the engine alive while you're sitting still. If it were me, I'd use some fuel injection cleaner and some MAF sensor cleaner. They're both super cheap and usually pretty effective. I'd also stand behind your car while it's running and see if you can detect the scent of unburnt fuel in the exhaust. If you can't keep it from dying while it's just sitting there, you might need to have a friend press on the gas a little bit. It there's unburnt fuel in your exhaust, then that's an indication that one of your spark plugs isn't firing. And that can be the cause of your problems too. Best of luck man.

jeffery 07 on March 15, 2012:

hi, yes it does shake for a few seconds.and yes i can keep it from dying by having my foot slightly on the gas.

Benji Mester (author) from San Diego, California on March 15, 2012:

Does it die immediately or does it shake for a few seconds and then die? Also, can you keep it from dying by keeping your foot pressed slightly down on the gas?

Jeffery on March 14, 2012:

i have a 89 Chevy s10 4.3 v6 it runs good while driving but when i come to a stop it's like it's flooding and just dies has took spells of doing this in the past and then straighten up but now it's staying like this would you have any ideal of what might be causing the problem. thanks.

Benji Mester (author) from San Diego, California on March 14, 2012:

Mike, it's difficult to say. It definitely could be the same injector, because it was a used one. It might have been near it's last leg when they put it in. But you might have also lost a spark plug. It's impossible to say really without taking it back to the shop. You may be able to get them to do some free work for you by complaining that the part they installed was faulty, that the car is having the exact same problem as before.

Benji Mester (author) from San Diego, California on March 14, 2012:

Cortney, what was the car acting like before you used the Lucas injector cleaner? What you're describing is a pretty rough idle. Either the engine isn't getting enough gasoline or oxygen, possibly both. If the Lucas injector cleaner didn't solve your problems, then it's probably another system that's failing like your spark plugs, MAF sensor, or air filter.

Mike on March 11, 2012:

Hi i have a 2001 audi a4 1.8t. About a month ago one of my fuel injectors went out (#2) i got it replaced at an audi shop with a used injector. Its been a little under a month and my car just started to misfire and lose power like before. Im wondering if its the same injector or a different one. I use seafoam in both my gas and oil at times but still find it weird it went out again so soon after being replaced. Also, i always use premium fuel, syn oil and changed spark plugs within the past month. Any suggestions?

Cortney on March 11, 2012:

I put Lucas injector cleaner in my car, i have a 99 Pontiac grand am. That was two days and two tanks of gas ago and my car is running funny. The whole car shakes and takes a while to take off when i stop and all day today as been shutting off every time i stop. What does this mean?

Benji Mester (author) from San Diego, California on March 08, 2012:

That sucks. Sorry to hear that. I've not heard of a crack happening there before, but if you found one, then it definitely seems like that's the source of your problem. That's an odd place to get a crack, but it is what it is. You'll probably have to replace the system unfortunately, or if you know a welder, remove the system and have them try and repair the crack for you, and then reinstall it.

carlos on March 08, 2012:

i have a 1995 gmc sonoma pick up and a few days ago i started to notice a strong smell of gasoline this after i degresed the engine with purple power..after looking for the source of the smell i notice a leak from one of my fuel injectors i replace the o-rings and still leaked so i replaced them again and i checked the retainer and its fine holding the injectors in place but the same one injector still leaking! could it be the injector body? i noticed a hair line crack right below where it plugs in. does this happen? any ideas?

Benji Mester (author) from San Diego, California on March 08, 2012:

Did this happen all at once, or did it get worse over the course of a few months? If it happened all at once, then you might be dealing with a misfiring cylinder or two, which is most often caused by spark plugs going bad or a cracked distributor cap. If the problem came about slowly, then hopefully the fuel injection cleaner will help. Other things that might help will be checking your air filter to see if it's dirty, and using some Mass Air Flow Sensor cleaner. I've written an article about how to clean your MAF sensor, which I've linked to in this article as well. How many miles does the car have on it? You may be due for a general tuneup, which can solve spark plug problems and other things that cause poor performance.

Susan904 on March 08, 2012:

Hi! I have a 2001 Ford Expedition. It has been starting and then sputtering and then shutting off. We changed the battery (it started once after doing this) we changed the fuel filter, same thing started right up and then the next day it starts sputters and shuts off...we have fuel injection in the gas (full tank)however, hasn't gone through...any suggestions? TY

Benji Mester (author) from San Diego, California on March 06, 2012:

Definitely could be the injectors. Could also be a dirty air filter, clogged fuel pump, or dirty MAF sensor. But fuel injection cleaner is the cheapest and easiest thing to use, so it's a great place to start.

Kevin on March 05, 2012:

I have a 2001 GMC 2500HD it shakes off the start and that is it, Had my guy hook up computer and tells me there is nothing wrong with the trans. It did have a couple of miss fires so I also changed the pulgs and wires...I then put some high octain fuel in it but still shaking when I take off hard...Could it be the injectors

Benji Mester (author) from San Diego, California on March 02, 2012:

I need a little bit more information. Are you saying that you don't have much power when you first start moving but once you get moving to a good speed then you don't have a problem anymore? Or do you have a lack of power at all speeds?

Kesha on March 02, 2012:

Hi, I have a 99 Cal. Catera and I'm having problems with when I'm driving it's starts out slow then wait to pick up speed can u pls tell me what that can be and what will help. Thanks

Benji Mester (author) from San Diego, California on March 02, 2012:

Hey Jan, yeah that's pretty high for an idle and yes, the higher the idle, the more fuel you're expending just sitting there. The idle is basically just the momentum it takes to keep the engine running even when the car isn't moving. Anything more than that is just wasted energy.

Jan- Malatsi on March 01, 2012:

Hi, I've corsa GSI 1.6, the idle is 1.4rmp is it normal or it could be there is something wrong? Also if the idle is too high is the car eating the petrol? Please let me know thanks

Benji Mester (author) from San Diego, California on March 01, 2012:

You should only put the injector cleaner inside the tank when you have a full tank of gas.

amber on March 01, 2012:

When Is The best time to put the fuel injection cleaner inside the tank or is doesn't matter

Benji Mester (author) from San Diego, California on March 01, 2012:

Check to see if there's the smell of unburnt gasoline in your exhaust fumes. Start your car and let it warm up a bit and then stand behind it and see if you can detect any unburnt gasoline smell in the exhaust. If it won't idle without someone stepping on the gas a little bit, then you'll need someone to step on the gas a bit while you try and detect the scent. If you have a misfiring spark plug, then you'll not be burning all of the gas that goes into your engine and some of it will be pushed out of the exhaust. That can help to determine whether or not you have a misfiring spark plug.

Andrea on March 01, 2012:

Everything started all at once, the rough idle and jerking when driving. I didn't even think to check the spark plugs. When I start it I can drive it to wherever with no problems then sometimes when i go to leave and come back home it starts. Theres no check engine light on or anything.

Benji Mester (author) from San Diego, California on March 01, 2012:

Hey Wanda, the MAF link is inside the article itself, 3rd paragraph down. You ought to explore the option of switching to a heavier weight oil. Your mechanic/oil change person should be able to give you some options for that based on where you live. Some colder climate areas require different oil than warmer regions. So I can't tell you specifically what oil you should use. But a 1999 Ford at 184,000 miles is definitely a candidate for a heavier weight oil like SAE 30 or 10w40.

If you read the article on MAF cleaner and decide that you don't feel comfortable doing the procedure yourself, you can always buy a bottle of the cleaner and bring it in with you to the mechanic and see what they'll charge you to do the procedure. It shouldn't be more than $50 or $75 in labor I wouldn't think. If you do both those things, as well as a bottle of fuel injection cleaner, I think you'll notice quite a bit of difference.

Benji Mester (author) from San Diego, California on March 01, 2012:

Andrea, if you've already used a bottle of fuel injection cleaner, then it's probable that something else is going wrong. You could try another one, but it might not do any good. If your fuel pump's clogged and it's inside the tank, then there's probably not much you can do short of replacing the whole tank. But there are a number of other things that might be going wrong as well. Your air filter or Mass Air Flow sensor could be dirty, possibly both. A spark plug might be misfiring. Or it could be your fuel filter, like you said.

Did the rough idle start pretty much all at once, or has it been gradually getting worse? If it happened pretty much all at once, then that's a good indication that there's a spark plug that's misfiring. This can either happen from the spark plug itself going bad, or from a crack in the distributor cap that sends the spark its electricity. If the problem has been growing more gradually, then it's most likely one of the other issues.

wanda on March 01, 2012:

I didn't get the MAF link

wanda on March 01, 2012:

I forgot to say that I use only 5w30 oil already.

Andrea on March 01, 2012:

Ok so I have a 2000 dodge dakota sport v6 with 150,000 miles on it. Here recently while I've been driving it jerks and when i'm at a stop light it idles rough like it almost wants to die but doesn't. I used chevron here recently it stopped for a week but started doing it again. I'm afraid its the fuel filter but i've been told with this year of truck the fuel filter is in the tank inside of the line. Any ideas? Would it be bad to try another bottle of chevron?

Benji Mester (author) from San Diego, California on March 01, 2012:

Wanda, it sounds like you have multiple problems going on. If you're leaking a lot of oil into your combustion chamber then you very well might have 1 or more fouled plugs which is where your misfire is most likely coming from. To deal with that, talk to your mechanic/oil change person about switching to a heavier oil like SAE 30 during the warmer summer months and maybe 10w40 in the winter. Since your truck is an older Ford, it should do well with an oil like that.

You can definitely try fuel injection cleaner. Chances are, you have some clogs in your injectors. The other things that might help would be to check your air filter to make sure it's not super dirty and to buy some Mass Air Flow sensor cleaner. It's pretty easy to use. I've linked to an article that I wrote about the MAF sensor that you can read for instructions.

Benji Mester (author) from San Diego, California on March 01, 2012:

Tavo, the change should be immediate. If the injectors are clean, then the spray should be fully functional. I'd give it 50 miles of grace period just in case, but if it takes longer than that, then you probably have something else going on.

wanda on February 29, 2012:

Hi I have a 1999 ford expedition that is cutting off when the gas level gets to 1/4 tank and I have had the fuel pump changed and now it shakes really bad when pressing on gas after cranking or moving from stop I thought it was misfiring b/c that's what my usual mechanic said then I had diagnostics ran at autozone and my jam (keep alive memory) has low voltage plus it is burning oil up but no leaks unless in fuel. Would fuel injector cleaner help at 184,000 miles?

Tavo on February 29, 2012:

Hey man, i took my truck for injection cleansing a few hours ago, my question is, how long does it take to notice a change? my truck had a misfiring because the previous owner used cheap gas, i have one month with this vehicle.

Benji Mester (author) from San Diego, California on February 27, 2012:

Hey Norman, it could definitely be clogged injectors. It could also be a dirty Mass Air Flow sensor or a clogged fuel pump as well. Since the fuel that runs the car is made up of both gasoline and oxygen, you need to make sure you're getting enough of both in the combustion chamber. If it were me, I'd use both fuel injection cleaner as well as Mass Air Flow sensor cleaner. I'll bet you'll notice a huge improvement.

Benji Mester (author) from San Diego, California on February 27, 2012:

Hey Rudez, haha not screamin. It's not your fault that they may have given you a bad pairing. It's possible that your fuel filter could be plugged, but I think it would be a pretty big coincidence if the fuel filter started acting up right at the same time that you changed your plugs. It's weird though for the guys at Autozone to give you wires that wouldn't match the plugs. If it were me, I'd check the plugs themselves to make sure they're functioning properly. Plugs have been known to go bad during installation. Sometimes there's oil in the spark plug tube, or if the plug gets knocked around a bit, the gap can change. If they're fine and working properly, I'd swap out the wires for new ones and make sure you get wires matched for the Bosch plugs. That should be an easy enough and cheap enough swap. There's nothing wrong with changing your fuel filter either. Can't hurt. It just seems like since your problems arose after the spark plug installation, I'd check that out first before moving on.

norman on February 27, 2012:

Hi, Im driving a Volvo S40 with 140000 km, I changed the filters but the rpms doesn't go above 3000 and if it does the car then vibrates, it also stalls at stops and jerks when I take off, what could be wrong and will injector cleaner help?

Rudez on February 25, 2012:

Hi, hello... You're gonna scream at me when i tell you this. But I have a 2007 V6 Mustang. I recently changed the spark plugs and wires for the 1st time. The car had 129,000 miles on it. I went with the Bosch Platinum+4 plugs, and I was given the Duralast wire set (part# 4735 at AutoZone). Since then, I've noticed that my car idles a little ruff. It was fine before. I use Chevron 97% of the time, and Shell the remainder of time. But I've never changed out my fuel filter.

In your opinion, would you say that perhaps it's something in my plugs/wire marriage? Reason that I ask, is that my wires get extremely hot. Or if I should swap out my fuel filter. Thank you.

Benji Mester (author) from San Diego, California on February 21, 2012:

I'm not sure actually. I've not done that before. Too much would probably cause negative symptoms though, as the cleaner doesn't burn the exact same as gasoline. I'm not sure how much you put in exactly, but the ratio is generally 1 bottle of fuel injection cleaner per tank of gas.

Benji Mester (author) from San Diego, California on February 20, 2012:

Charles, it sounds like something didn't go quite right with the tuneup. What work did they do exactly? You definitely shouldn't be experiencing rougher idle and poorer fuel economy after a tuneup. Depending on what they did, there are cases where spark plugs can get fouled during or directly after a tuneup. There are a couple of reasons why this might happen, but we won't get into those reasons. If I were to take a guess, I would say that your spark plugs were either gapped improperly, installed improperly, or got fouled right away. Turn on the car and stand behind it while it's in park and see if you can smell any unburnt fuel coming out of the tail pipe. That'll be a clue as to whether or not your spark plugs are in good working order.

Benji Mester (author) from San Diego, California on February 20, 2012:

Yaz, So it only happens on a full tank? That is odd. That's the reverse of what usually happens. When you say it takes 10 minutes to work, can you describe what you mean a little bit more. Does it not even turn on for 10 minutes or just run rough for the first 10 minutes? You might try filling up with premium next time and see if there's any difference. If it runs better on premium, that'll indicate that your fuel/air mixture is too lean for some reason when on a full tank, though we still don't know exactly why. But it'll be a step in the right direction.

Charles on February 20, 2012:

I have a 2001 pontiac montana and I had a tune up done to it yesterday and for some reason now everytime I come to a stop it shakes a bit like it wants to turn off. Could it be a fuel injector problem or can it be something with the tune up because it started to shake everytime I stopped almost right after the tune up??

Yaz on February 20, 2012:

I have a 2004 Sonata, every time I fill it up with gasoline, the car takes like 10 mins to work. I keep trying to switch it on but with no use, it only happens when i put gas in the car. I tried putting a bottle of fuel injector but didn't seem to do anything, Any suggestions?

Benji Mester (author) from San Diego, California on February 18, 2012:

Hopefully it won't happen again. You should check to see if other owners are having recurring similar problems with that year and model. But with the amount of things you had worked on and replaced, I would think you solved the problem. Keep your fingers crossed though.

Jean on February 18, 2012:

I have 2008 buick enclave. Engine light was on and DIC read: traction control off service stabilitrak. Ended up having the fuel injector serviced along w/throttle body, airplenum and intake. Also had mass air flow sensor replaced under warranty. Oil chabged was performed and new air filter put in. What to do now to keep this from happening again??

Benji Mester (author) from San Diego, California on February 18, 2012:

Yeah newer vehicles shouldn't have injector clogging problems. It takes quite awhile to build up. That being said however, fuel injection cleaner is cheap, and doesn't hurt the vehicle. So you might just want to try it and see if anything gets better. But from what you're describing, it sounds more like your lack of power is coming from perhaps misfiring from a faulty spark plug or something similar. If you have a bad spark plug, then one of your cylinders won't be operational and you'll be suffering from lack of power for sure.

Here's what you might try. Turn on your car and stand behind in while it's running in idle. If you smell the scent of unburnt fuel coming out of the exhaust, then most likely your problems is stemming from one of the cylinders not firing. At that point, I'd change the spark plugs and perhaps do a full tuneup. If you don't smell the unburnt fuel, at that point, I'd try a bottle of fuel injection cleaner to see if it helps anything. Best of luck.

tsengel on February 18, 2012:

i read through the article and i think i have to try this injector cleaner. but before that i would like to know little more.. you are saying that new vehicles should not have this problems. well i have a 2011 toyota camry le has only 34,000 miles on was perfect but then after two weeks from my purchase i noticed that car is idling low around 500-600. and also it would not accelerate as fast as it used to. and stepping on gas gotten more harder.. and car seems to hesitate to accelerate on 1 to 3rd gear. and it feels like my car is dragging something heavy. my car was a rental car and right when i bought it i filled it up with 91 octane from shell and i filled it twice. when i saw that my car was losing power i switched it to 87 and still have that problem.. does it sounds like a fuel injector problem?

Benji Mester (author) from San Diego, California on February 13, 2012:

Hey Tom, yeah seafoam can be added directly to your intake manifold, but it takes a little bit of know how to do it. You have to run it in through the vacuum line. It's definitely a worthwhile procedure to do if you're up for it. Backfiring can be a tricky thing. It's pretty common for backfiring to only happen in certain instances like what you're describing with the pedal half way down. There could be a couple of things going on. Since the truck is fairly old, you definitely might have some timing/compression issues, like your friend mentioned. If things are just clogged, then cleaning the intake manifold will definitely help, as will checking your spark plugs, coil, air filter, etc to see if anything needs to be changed.

Tom on February 13, 2012:

sorry, seafoam worked the first time. and... i also heard you can add seafoam into your intake. would you recomenned that?

Tom on February 13, 2012:

Hey man, i have a 94 dodge dakota v6 and i am having a problem of the pedal being pressed halfway down and getting some back firing and it is also acting like it is losing fuel pressure. It worked for the first time it had started and it went away and came back about a week later. a guy i have talked to said it sounds like i have jumped time on it. again it only backfires and misses when the pedal is halfway down i can floor it and it would be fine

Benji Mester (author) from San Diego, California on February 11, 2012:

Hey Ylla, it's tough to say what's causing that without being able to actually look at the car. Misfiring is generally caused by either 1) a lack of spark from the spark plug, 2) poor timing, which causes the explosion either too early or too late, or 3) a lack of the proper amount and ratio of fuel in the combustion chamber. So if you're experiencing misfiring, you'll either have to change your spark plugs, get your timing looked at, or make sure their aren't any clogs to your fuel system or air filter.

Benji Mester (author) from San Diego, California on February 11, 2012:

Hey Gaby, it definitely could be related to the fuel system. Any form of clogging, whether it's in the fuel injectors or the fuel pump will definitely cause the symptoms you're describing. The only odd thing is that it doesn't happen right when you start the car up. That's fairly odd because cars run better after they've had the chance to warm up a bit. I suppose it's possible that the extra pressure of having a full tank of gas as opposed to an empty tank, forces the fuel to flow better. That would be my guess. If that's the case, then it's not probably clogged injectors so much as a clogged fuel pump of fuel filter.

Ylla on February 08, 2012:

Hi benjimester ask you again i brought my car to the mechanic n they change the fuel filter but it get worse it misfire especially when i ease on the gas and try to speed up again what's causing this will it lead to bigger problem if i ran it coz i only have 1 car

Gaby on February 08, 2012:

Hi Benjimester-

I have a 2001 Ford Focus with about 137,000 miles. The engine was replaced about a year and a half ago with one from a junkyard. The odometer on the junkyard car had over 200,000 miles but my mechanic wasn't sure if the engine had been rebuilt or if those were original miles.

My car has been starting fine after it rests overnight, but occasionally if I drive it to run a quick errand the engine seems to misfire when I try to start it again. It will take a split second longer for the car to start and then shake quite a bit for about 15 seconds before everything comes back to normal. It seems like every time this has happened the fuel tank has been around 1/4 full so I'm not sure if that is related or just coincidence. This weekend I made a few stops within an hour or so on a full tank of gas and it started fine every time.

Spark plugs, coil pack, and battery are new within the last year. There is a small crack in the EGR tube that is going to be fixed soon.

Do you think this problem is related to the fuel system?


Benji Mester (author) from San Diego, California on February 07, 2012:

It's possible if he used too much. Then definitely. If it were me, I'd drain all the oil out and start over again. That way, if he did accidentally add too much seafoam, it'll fix the mistake and you can start over. But it sounds like the engine is pretty beat up already and needs to be rebuilt.

Gary on February 06, 2012:

looking at pickup truck for sale - here is what the guy says : The motor did turn over last time i started it. It makes a lot of noise so it will need to be rebuilt or exchanged with a working motor. I was doing an oil change, to which the engine ran perfectly, and put some seafoam in the block to clean it, after a few minutes it started making all kinds of noise so i shut it off. Started it again and it is still noisy. I haven't ran it again so i didn't damage it any worse than it was.

do you think the seafoam caused this ? ant easy answers ? Thanks

Benji Mester (author) from San Diego, California on February 06, 2012:

Hey guys. Sorry I keep getting behind in the comments. I was out of town again.

Gus -- Having gas from different places shouldn't cause problems, but it sounds like you might have gotten some bad gas from one of them. Your friend's suggestion sounds like a good idea.

Yila -- Vibration happens when your engine gets starved of fuel. It shakes before it eventually stalls. It's not good to run your engine like that so you may want to think about using some injector cleaner and check your air filter as well.

Casey -- Yeah it's safe, although a 12 gallon tank is pretty small. But if you're worried, just pour in 3/4th of the bottle. It should still do the job.

Casey on February 05, 2012:

Hey, Benjimester. I'm about ready to go on a roadtrip and was going to use some fuel injector. On the back of the bottle, it says to use no more than 22 gallons of gas. Being 12 or 15g tank, is it safe to add the whole bottle, or do I need to put it in differently?

Ylla on February 04, 2012:

Hi benjamin just want to ask what would be the problem of my car if the idle is low cause everytime i slow down it vibrates n like tsug tsug sounds

Gus on February 02, 2012:

Can topping up with gas from different places cause my check engine light to come on and cause the car to stall when idling? My wife was getting low on gas so she got $20 worth to hold her over (to expensive to fill up) until she could fill up. So there is gas in the tank from 3 different places. The check engine light came on. I took the car to advanced auto parts and had them check the codes. They said it could be an oxygen sensor problem. Then a few days after that is when the car would idle low and stall at a stop light. I have to put it in park and rev the engine until the light changes. A friend told me to run out the tank then add a bottle of Heet and put in Lucas fuel injector cleaner and then see if that helps. The car is a 2004 Mercury Monterey with about 75,000 miles.

Jesse on February 01, 2012:

Hey thanks for the help so far its Jesse again, I am losing the 500rpms well driving any ideas what could be causing this??

tracy on January 31, 2012:

Hi. I hada tune up last march when the engine light was flashing and i had a bad coil replaced. I know I'm due for an oil change.

The thing is, we don't really want to put a whole lot of money into the car since we plan on buying an "almost new" car come april or may. I have an appointment tomorrow to have a mechanic look and tell me what's wrong and how much it will cost to fix it.

Benji Mester (author) from San Diego, California on January 31, 2012:

Hey Joseph, yeah blast cleaning the injectors works well too. But additives are a normal part of gasoline. They're in there all the time. Having a few more every once in awhile doesn't really hurt.

Benji Mester (author) from San Diego, California on January 31, 2012:

Hey Megan, losing fuel economy is pretty standard for aging vehicles. That's good that you had the spark plugs changed. The next time you get an oil change, you could ask the guys at the shop to do a couple of jobs for you that will help boost your fuel economy. One is to change the air filter if you haven't had it changed in awhile. Two is to have them clean your intake manifold. That will usually give you an extra couple of miles per gallon back and they do it at a lot of the major oil change places like Valvoline. And it usually only costs about $75.

Benji Mester (author) from San Diego, California on January 31, 2012:

Jesse, are you losing the 500rpms at idle, or just sudden loss of power while moving? If it's at idle, then you probably could benefit from some injector cleaner. And to answer your second question, you should wait until you have a full tank of gas before pouring the injector cleaner into the tank.

Benji Mester (author) from San Diego, California on January 31, 2012:

What's up guys. Let's do this one at a time.

Tracy -- If it's still stalling after the tank is empty, then your problem isn't the fuel injectors. You don't want to just keep dumping injector cleaner in there. There are a number of other things that can cause stalling and poor engine performance, even simple things like a dirty air filter. Have you had a tuneup recently? I just ask because you're at about the mileage where you might benefit from a major tuneup.

joseph on January 30, 2012:

cont use any addatives at all you will harm the fuel pump...just go to your local mechanic, once every cpl years and have him blast clean the injectors i have a 2003 ford ranger edge and ive done this regularly ad it runs smooth as silk those cleaners are a waste of money

Megan on January 30, 2012:

I have a 2007 tahoe with 79,500 miles on it. It has lost about 4-5 mpg. I was averaging around 16-17 mpg and now I am at 12. I went and had it checked out and the guys just replaced the spark plugs, said oil and filters looked fine. The mpg has not gotten any better. I was going to buy some seafoam and try that. Any idea on what could be causing the drop in mpg?

Jesse on January 30, 2012:

Hey, I have a 2000 grand am last few weeks I notices that when I am driving I would lose about 500 rpms and ideas what is causing this problem. And can I use fule cleaner on a full take of gas or should I wait till its empty

Tracy on January 28, 2012:

Hi. I have a 2001 taurus with 135k miles. The engine light came on andi went to autozone they read the codes at 171 and 174. The idle was a little rough leading up to the light coming on. A friend recommended that we get the fuel filter replaced and put a bottle of fuel injection cleaner in. The morning before i dropped the car off at the shop it started sputtering at stoplights and then actually stalled at the light right before i dropped the car off. When i picked the car up i noticed better performance when driving but the sputtering came back on my way home and it stalled at a red light. I did add in the cleaner on my way home. My question is when should i expext the sputtering and stalling to get better? If it continues through 1 tank of gas should i try another. The brand i used was gummout

Benji Mester (author) from San Diego, California on January 23, 2012:

Chad, you're welcome! What you're experiencing is pretty common in aging vehicles. I bet you'll notice a difference after all the work you did. Rough idling is usually a combo of a variety of small factors, and isn't usually indicative of any major problem in the car. Hopefully by the time you read this, your car will be much smoother on the idle. If not, let me know and we can troubleshoot.

Chad on January 21, 2012:

First I wanted to say thank you for taking the time to answer questions like these. The world needs more people like you! My question pertains to my 2004 dodge neon. It has about 136,000 miles on it. When I stop at red lights my car whole car will shake/ idle and my lights flicker unless I turn my a/c on. It doesn't act up if I give it a little gas while I'm waiting. It only happens when the vehicle is in drive. I had my fuel filters/air filters and oil changed yesterday and today at Wal-Mart I was getting new tires and decided to try out their 20$ fuel injection cleaning. I haven't gotten a chance to drive the vehicle yet but do you think this might solve the issue I'm having or might there be something else that's wrong with the vehicle?

Benji Mester (author) from San Diego, California on January 20, 2012:

Hey Jaye. You'll notice a change in idle pretty quick. And by the time you use the whole tank of gas that the injector cleaner is in, your clogs should be mostly broken up, depending on how bad the clogs are.

Jaye on January 20, 2012:

How long does it take for a bottle of fuel injector to actually clean out your injectors before you see a noticeable difference?

Benji Mester (author) from San Diego, California on January 16, 2012:

Hey Abbey, that's not a good situation. Sorry it took me awhile to respond. You've probably already brought the car to the mechanic by now. There are a couple of things that you can try. One is to open the hood of the car and remove the air filter and leave the cover open. That'll make it so that you have the maximum amount of air flow to your combustion chamber which will hopefully help you to start the car up and burn out some of your fuel injection cleaner. If that works and the car is on and running, rev the engine for awhile and see what you can detect. See what kinds of scents and smoke are coming out of the tailpipe. If you have the scent of unburnt fuel, then you might have a fouled spark plug on your hands that you'll have to replace. If you have a lot of dirty smoke coming out of the tailpipe, then you probably are burning oil, which can also cause a fouled spark plug. Hopefully keeping the engine revved for a bit will help the injector cleaner to break up potential clogs. At least if you get the car running, you can take it to the mechanic and not have to have it towed.

Maybs -- You probably have a clog somewhere. That's usually what causes low idle. But it could be a number of things. It could be the air filter, the fuel filter, fuel injectors, or even a dirty throttle body. You may do well to get a general tuneup where they change your spark plugs, distributor cap, air filter, and clean your injection system. You might also see how expensive it is to have your throttle body cleaned.

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