Idle and acceleration problem

[treklav]

Ok. for the past week ever since i got my car back from the shop, the car seems to idle just fine. then about 2 mins after starting the car it decides to drop from abou 1500rpms down to about 7-800 rpms almost killing the car, then it goes all the way up to 2000rpms and then back down to 1200 rpms and stays there. then it will do that several more times. it's really strange. then when i go to put the car into drive the car acts like it's gonna die and then recovers. but here's the kicker...whenever i accelerate it chugs down for a second or two, then finds itself and takes off. It's really wierd. I'm thinking one of three things, or all three things combined, but whatever the case may be i'm thinking maybe the fuel filter, ignition coils, or the throttle position sensor. Not sure if any of these will help or not, but it's worth a shot i guess. just wondering what you all thought. Oh and my car takes longer to start now than before i took it into the shop too. interesting.....

[sped214]

Check the IAC valve also. make sure the pintle moves without restriction, and the valve itself is fairly clean, and is not leaking when installed...

[treklav]

ok. where exactly is the IAC valve?? and how do i check to see if it is working properly?? i haven't dealt with this before :D

[sped214]

it's on the passenger side of the throttle body, closer to the firewall than the TPS sensor. held in by 2 torx type screws.

[jhkcam]

I had a very similar problem about a year ago and it turned out to be a bad connection somewhere with the spark plugs (wire i think). The bad connection would cause the spark plug to work on and off causing all the rough idling, rough starts and bad noise.

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1995 camaro 3.4 (A4)
mods: K&N FIPK air filter; SLP cat-back on the way!