Just started recently. When my 99 z/28 is sitting at idle, after a few minutes the rpms begin to rise without me touching the pedal. It only rises about an extra hundred rpms, then it drops low and comes back to its normal idle. When this happened, I blip the gas just up to 1500, the engine revs up, and then sort of hangs there for about 5 seconds, like something is holding the engine steady at 1500 rpms, then it slowly dies down idle again. What is making it stick like that? Any help would be great.

 

maybe a dirty iac or tps? I dont know, i didnt think that was abnormal. Sometimes mine does the same thing but only as often as once every couple weeks, and other times it acts normal.

 

Spray your throttle plate down w/ some Sea Foam. Get the passages at the top too. Or you could just take the IAC off itself and clean it.. THat usually helps a LOT.

 

IAC is making changes to maintain the idle. You probably need to clean it.

 

Is the car modified? If so, what mods? Cleaning the IAC valve will help some. You may have to clean the MAF too. If the car is modified (ie cammed), you may have to play with the set screw on the throttle body.

 

Just some basic mods: lt headers, magnaflow cat back, lid, ssra, maf.

sorry to ask, but what is an iac? im still pretty noob on learning about modding my f-body.

 

iac = idle air control

 

The IAC is a valve that mounts on the side (drivers side I believe) of the throttle body. It allows air to pass into the intake as it opens. It's used in conjunction with minor spark advances and spark retards to maintain a desired idle speed. You should check a manual (usually sold at Autozone type places) for more info. It's not rocket science though...

 

ya its definately not rocket sciencce, if you are even a beginner to tools, this should be easy for you to do.

It takes me about 10 minutes to get the throttle body off and the iac taken out. you could do it easy.

Now the IAC is the little metal part held in with 2 star screws and a plastic base. It also has an electrical connector on it. And be careful to not drain coolant all over your belts when you pop off the TB coolant hoses.

 

What particular cleaner i should use once i have it dismantled? And is there anyway to keep it from doing this again?

 

MAF cleaning solution they sell it at your local parts store.

 

Dont drive your car? carbon build up will always happen.

Clean off your MAF too. Pull it out and spray down the three small wires but dont touch them. if they break you bought an expensive part...

 

lol alright. thanks for the help guys