idle problem..

[justnobody]

first off i have a 99 gs auto.. only with i/e

when i start it up, it idles okay .. then after a minute or 2 the it goes from 1000 to 1200 then back to 1000 then 1300 then down to 1100 then up to 1400 then down to 1100 then up to 1500 then goes back to 1000 and stays around there. i know theres dozens of these threads around but mostly everyone i saw was for turbos cars, or high idle to 2000- 3000, so idk maybe my problem is different. theres only 2,000miles on my engine. Is this normal? i only realized this when it started to get colder out and my car stays on park when this happens. The place i got my engine with warranty cant see me till next week, so im stuck for a week to try figuring this out. Is this a expensive or serious problem?

 

[silvreclips]

Does it do this when the motor is fully warmed up?

 

[Shadow98]

I'm going with IAC

 

[justnobody]

only happens if its really cold out, and only happens the first time i turn on my car, i turn my car on later on the day and its normal idle. Idk whats wrong seems like when its cold my idle bounces, and my key gets stuck in the ignition(only comes out if i blast the heat full on), when its not cold everything works fine ... so far.

 

[95 'clipse RS]

are you getting a CEL? i had a problem like yours and it was the intake gasket (just keep that in mind). though it does sound like the IAC (idle air control) motor. you can try to take it out and clean it, but that may not work. also there are other thing that may play a role in this idle problem. like vacuum leaks, check all hoses for cracks holes, deterioration, anything of the sort. check all hose connections to the intake manifold, and PCV (positive crackcase ventilation) valve to valve cover, might as well check the PCV valve too. then you can double check the hoses that run the EGR system. if all is fine, your problem may lie within the ISC or somewhere else like wiring, IM gasket, or ECU. hope this help ya out some man, i was pullin my hair out trying to figure out my problemWTF

 

[justnobody]

well when i went to get my oil change 2weeks ago, they told me i had a valve cover oil leak, but they said they cleaned it up, but i guess its back then, they told me i should go back to them next oil change to see if they have to replace the whole thing or what. thanks for the helpful info.

 

[95 'clipse RS]

an oil leak with the valve cover isnt too serious unless youre leakin tons of oil, and still then it wouldnt cause the problem that you are having now. are you gettin a CEL?

 

[justnobody]

nope, not getting any check engine light on.

 

[95 'clipse RS]

hmm thats a little odd, plus the fact its only doing it while the engine is cold. when mine had the screwed up gasket it still had a code. but it also had the screwy idle all the time. id check over the vacuum lines and pcv valve first and then possibly check ISC, ECT (engine coolant temp) sensor, and the wiring. And maybe hookup a vacuum guage at cold idle and see what it reads. the ECT sensor will cause the engine to run rich and raise the idle on cold starts, to warm the car up sooner. just for reference. hope this helps man

 

[justnobody]

alright thanks for all this info. i very much appreciated it.

 

[Shadow98]

Have you checked (or replaced) your IAC, yet?

 

[Locke]

the fiav could be a possibility or the O2 sensor.
recently replaced my ISC and unstable idle is still present on my car
but who knows

Pssst.. Pssst...

Aside from being posted in the 420a Bolt-On tech and from his profile stating he has a NT, the first line of his first post clearly states that he has a 2gnt.

No FIAV.

 

[99RedGs]

Wait, so when it is cold and you have the heat blasting the idle jumps around correct? Or is it independent of the heat being on? If you are running the defroster then you need to remember that it runs your a/c. This would cause your car to try and compensate from the drag it is receiving and the idle would move around. Also, if you have the heat blasting, the rear defroster on, your stereo, etc you are pulling a lot from the car. Then your car would need to speed up the rpm's so the alternator can put out more charge and the a/c can keep up with the blower.

When your car is cold and started it is also running in Open loop mode. If you don't know what that means, it basically means your car is operating off of a preprogrammed fuel control and not relying on the O2 sensor to adjust your mixture. This is because the exhaust is not to temp and the O2 sensor is not able to send accurate data to the computer. This could have an effect on cold idle.

I'm not sure why this is a problem because it doesn't affect how your car drives. It just affects the 5 minutes your car is warming up and your car idling up to 1500 rpms isn't really that bad.

 

[Locke]

If you are running the defroster then you need to remember that it runs your a/c. This would cause your car to try and compensate from the drag it is receiving and the idle would move around.

You do bring up a good point. The a/c does run when the defrost is on, but it should not effect the idle. The ECU knows when the A/C is on, via a pressure switch, and compensates for the load by opening the IAC more to maintain a steady idle.

Although, the idle would only drop when the compressor was running.

I'm not sure why this is a problem because it doesn't affect how your car drives. It just affects the 5 minutes your car is warming up and your car idling up to 1500 rpms isn't really that bad.

It's not a big deal, but it is not as intended. Something is wrong.