Fuel system cleaning for rough idle??

[waynedog]

My 2006 Avalon Limited idles rough at times (at stop lights). Should I get a fuel system cleaning done? It has 52k miles and has probably not been done in the past. Would a fuel system cleaning help with rough idle? Can I do this myself or do I need to take it to the dealer?

Thanks

[TrailDust]

Fuel system/injector cleaners can only do so much. What kind of driving do you do with your Avalon?

[waynedog]

Mostly around town driving, some on the road. Only about 12k miles per year.

[TrailDust]

Then I would suggest having your injectors cleaned. Fuel injected engines don't do well under the conditions you describe, and the injectors can get clogged over time. Fuel additives can only do so much, and a more in-depth maintenance effort is needed. If you go that route I'd highly recommend going to a private mechanic than a dealership. Better work, better prices.

[pmesfun]

Check the vacuum houses around the air filter box(as well as the air filter), and reset the ECU by pulling the EFI fuse located in the fuse box adjacent to the battery(for about a minute).(Presets will not be erased.)

[oilman]

I cleaned my air flow sensor recently and improved my fuel consumption by at least 2mpg on highway - this is easy to do and may solve your problem.

[OpticNerve]

First, I would go to Auto Zone and ask them to check for any pending DTC codes. Sometimes you will find a code or two that does not set off the Check engine light. If no codes are found, I would buy a can or two of Sea Foam from the folks that checked for DTC's. When you get about half empty put a whole can of the Sea Foam in the gas tank. Make notes of what is going on just prior to getting the rough idle. Is the car fully warmed up, what is the temperature outside, what octane level and from who are you getting your gas? Rough idle is a good problem to solve. It could be a lot of different things. Like moisture in the gas, a dirty MAF sensor, fouled up injectors, a bad thermostat, etc, etc. Give the Sea Foam a shot, and report back. Over

[Mike Murrell]

Originally Posted by waynedog

Mostly around town driving.

As stated above - Seafoam in the gas tank first. You may need to do a couple of these and try to get it out on the highway for some > 40mph driving. I know we're talking about fuel injection; not carburetion; nonethless, too much city driving can cause carbon buildup in the combustion chamber.

So many things that can cause rough idle....a long list indeed.

I used a can of BG44K in an older gas Mercedes a few years ago and was amazed at what it did for that car.

[waynedog]

Thanks for all the recommendations everyone. I have added a can of SeaFoam to my tank and I will see if that helps.

[waynedog]

Well, I added the can of Sea Foam and ran it though one tank. No difference in idle problem - still idles rough at stoplights. Any more suggestions?

Thanks

[pmesfun]

What is the rpm at idle?

[waynedog]

My rpm at idle is ~600 rpm.

[leakyseals]

Fuel cleaners with additive PEA are the only ones proven to do anything. techron complete fuel system cleaner concentrate and Redline Si-1 are 2 with PEA. Requires 2 bottles, 2 consecutive tankfuls. recommend you change your air filter, clean the MAF with MAF cleaner, use the rest of the MAF cleaner to clean your TB. Be sure to spray the IAC hole really good. Consider using a thinner synthetic oil. That combo should smooth things out

[OpticNerve]

Leakyseals and Mike have good suggestions. I have tried Techron and BG44K and I think they both work. I also have had good luck using Seafoam. My son has a 2003 Sentra which would not idle after start up. I took the brake vacumn hose off and slowly sucked in a can a Sea Foam as directed on the can. It cured the no idle problem on the Sentra. I think cleaning the MAF sensor is worth it, as is a new filter, if the old one is north of 30k. I would be careful cleaning the TB. It's ok to spray it with TB cleaner, but don't wipe it with a rag. I did that on a 2003 Lexus and it went into limp mode. The TB plate is very sensitive, and I must have confused the ECM. If trying things like this interest you, then spending the cash and time to try fixing this yourself, is worth the experience. If you, don't have the interest or time, then take it in. Some dealers and independents use Motor Vac, SnapOn, and others use BG products and machines which do the job very well.