I noticed it when I was running with one notch before "E", and I was coming to a stop. My RPMs dropped to what looked like 250ish or so, the first line, and the car was shuddering for a bit, then they climbed back up to the appropriate RPM. After filling up with teh standard 91, it still was doing that. I seafoamed and changed the oil (i was about 1k overdue) in which my CEL and VSA light came on. The VSA light reset when I turned the car off, but I had to clear the CEL by disconnecting the battery.... After that no more lights, but the car still has that intermittent idling problem.

it happens when driving for at least 30 minutes with the temp being in the 60s. i have yet to notice it during a cold start, but its doing it after its been running for a while, yet its not that cold out. Although I have noticed it takes the motor a tad longer to turn on in the cold mornings. Would that be a spark plug issue? or a coil pack issue?

Does anyone have any ideas as to what may be causing this? I would like to resolve this without having to go to the dealership, but if I have to... I will. Any help is appreciated!

(I posted this in a different thread, but got no responses... maybe since it was an old thread maybe?)

 

-bump

 

You might try Lucas Fuel system treatment. I had the exact same problem last summer. Mine got to the point where it would occasionally stall at idle when I shifted into gear. I put a bottle of Lucas into the tank and haven't had a problem since. The only thing I can figure is that crud builds up on the injector nozzles over time and eventually causes problems like this.

 

would seafoam do the same thing as lucas?

i know it does the same if used in the gas tank. If not, well then I guess I'm getting the Lucas.

 

I don't see why not. It serves the same purpose and is a highly regarded cleaner amongst the fellow AZ'ers.

 

Well, I tried the Lucas treatment. Put it in when I was approx. a 1/4 tank. I thought everything got better for a while, then it would start to drop to 250ish or so when I would come to a complete stop.

I tried Seafoam as well, in the next tankful. So far, I havent really seen improvement, but its still to early to tell.

 

seafoam needs to be used a 2ox product per 1 gallon of gas or 1/4 tank of gas add 1 can
Sound like a dirt problem in the IAC Idle Air Control and possibly dirty throttle body plate

Seafoam the intake manifold, vac line method too- that cleans valves and pistons.

 

EGR, IAC, PCV..........these items may need attention. Also, if the CEL was on, your answer may be sitting right there. Good luck !

 

there has been many threads about this same issue, and i dont recalling ever seeing a diagnosis or a fix.

 

IAC is usually the end cause

 

I see 2 problems. Either the IAC or the TPS. Take the IAC off and clean it. Clean your TB while at it. Some things need you to physically get in and clean it.

TPS cant be replaced and you will need a new TB

 

when you take off the throttle body and intake manifold to clean everything, do you need new gaskets, or will they be ok to use again?

 

call me a noob, but what is the TPS?

Mike told me it might be the IAC, but we havent exactly pinpointed it yet. Maybe we'll clean it if he's not too busy installing his newly acquired tranny and stuff. Obviously if I remove the IAC/TB, i'll need throttle body cleaner... any preferences as to which one is better? or does it not matter, since they all do the same thing?

I noticed it started to do so after I cleaned my CAI filter, could it be due to excess oil that was applied to the filter? I probably should have mentioned it sooner, but it just came to mind...

also, like burnerjunky mentioned, will I need new gaskets or be able to reuse the old ones?

how would I seafoam the intake manifold? through the vac line method right? or is there another way you jedis have yet to teach us padowan(sp?)

 

seafoam vac line method gets it right to the injectors, valves and piston tops.
any brand throttle body spray cleaner- find next to carb cleaner -but is more gentle around plastics

IAC located on bottem of TB assembly- remove- invert-remove screws- clean-yayda
If the filter was overoiled that will get on the TB plate and cause probs
Give it a spray out and see what comes out
Most filters need very little oiling to be a spec, so if you think that may be the cause- do it first, pull a front plug -becasue you can reach them and see if oiled up
Seafoam will fix that no prob

 

wat about the gaskets though.

 

What about the gaskets. I have heard that you should replace the throttle body gasket if reemoved, but I neer did, and I took my TB off more then a stripper takes off her clothes. Ran just fine..... till the tranny died.

I think his problem may be the IACV or the fact that he drowned the filter in oil when he cleaned it. I told him it was too much, but he listened to his girlfriend instead of me......


RIght Frank!

 

If you take the TB off you will NEED a new gasket. Its a paper style. There is NO need to take the TB off to clean the IAC valve, and that gasket can be reused.

TPS is throttle position sensor.

I doubt its too much oil. We dont have MAF sensors which are usually what gets damaged by excessive oil

 

oh then I suck, but I thought thats what it was.

I agree the gasket should be reaplaced, but I never did.

Everytime he tried to show me the idle problem it doesnt do it, its like a sporadic kind of thing.

 

same prob as me...but diff symptoms...ill try cleaning the iac as well..

 

iac=part#2?

 

yes part #2

 

Yes. its a rubber gasket and you should be able to reuse it. Just make sure its seated properly or you will have a leak and will cause issues.

 

Haha, you did tell me that it shouldnt make a differerence if i added more oil to it. so dont give me that! haha. i wanna clean my IAC now...

 

One other thing... would the IAC being dirty/clogged/etc, cause the car to not start as easily as it normally did?

for example, ill go to fire her up, and there are some times where it takes an easy 2-3 seconds of just cranking to get it to catch and turn on... there have been instances where the car doesnt start as well (that birthday party at the park down in sylmar, mike). it doesnt just happen in cold weather, but when its warm as well. The IAC is to blame on that one right?

 

i swear its a different thing every time! bah.

so i went to start up my baby after work... it cranked for maybe a good second, caught... sputtered at about 500rpms for a quick second, then proceeded to idle at about 1250rpms. after my nice 30 mile commute, i checked to make sure it wasnt doing it again, and lo and behold.. it wasnt.

this is after we cleaned my IAC as well as replaced my spark plugs last week. i really hope dont want it to be the TPS or anything like that. im starting to get frustrated with this...

 

Stop being a homo, take it to a mechanic (not me) and get it checked. then tell them to fuck them selves when they try to charge you a million dollars to replace a sensor.

 

Does anyone ever get their issue fixed? I never see what was the cause and I am searching for a solution to my stalling issue.

 

I'm dropping mine off at the dealer tonight and they get it for the weekend. Hopefully on Monday or Tuesday I'll have a cure to my issues:

- Intermittent surging forward at a stop with the trans is in Drive. If it's going to happen it will be in the first 15 minutes or so of driving and usually when it's cooler out.

 

- Occasional loss of throttle response from about 15-25 mph when accelerating. If I stomp on it, the car sputters and almost dies, then kicks back in to where the throttle is at and jerks forward. If I don't stomp on it and hold the pedal steady, the engine and accelerating come back after about 3-8 seconds. Very strange

- Also, some days the car feels like everything is running how it should and then occasionally it just feels like it is off. When it's off it's a little rougher at idle and driving and a little louder.

 

Mine quit doing the whole idle thing after I cleaned the IACV. Throw some seafoam in the new location shortly after doing so, and that should clear up most idle problems.

 

If the surging is more prevalent when the engine's still cool, possibly the coolant's thermosensor (ECT) or IAT is not functioning ideally ? Hopefully the dealer can diagnose this problem without gouging your wallet too badly ! Good luck and let us know how well they did.