Rough Idle
Thread Starter
Racer
Joined: Aug 2002
Posts: 402
Likes: 0
From: Central IL
Rough Idle
My car has a slightly rough idle in gear. Is this normal? I have not noticed it before. I think it may be a carbon problem (30,000 miles), as it has no miss at over 1,000 rpm. Idle in gear (A4) is about 600. maybe I'm just paranoid
Drifting
Joined: Feb 2000
Posts: 1,922
Likes: 0
From: Boulder, Colorado
Re: Rough Idle (belair55)
I just changed the intake manifold on my car, and while I had it apart, I noticed gunk buildup on the inside of the throttle-body, at the edge of where the butterfly valve is when closed. I cleaned it out, and it seems to have improved my idle on cold starts a little bit.
I tried changing plugs before that to see if it'd make a difference, and my plugs were alll perfect (no missing pucks).
Good luck,
:cheers:
I tried changing plugs before that to see if it'd make a difference, and my plugs were alll perfect (no missing pucks).
Good luck,
:cheers:
Team Owner
Joined: Mar 1999
Posts: 28,753
Likes: 9
From: San Jose/Bear Valley CA
CA Events Coordinator
Re: Rough Idle (belair55)
It could be a bad coil... check the coils by hooking up a timing light.... then watch for a steady rythm from the coil.
vetterdstr :cheers:
vetterdstr :cheers:
Instructor
Joined: Feb 2002
Posts: 233
Likes: 0
From: Warner Robins Ga.
Re: Rough Idle (Miles in Michigan)
Hmmmm...just guessing but I'd be willing to bet you have a dirty(carboned up) and/or worn IAC(Idle Air Control valve). I don't have a Corvette but these valves are common with most fuel injected engs.
They are usually easy to remove--then flush/squirt solvent inside of it where there will be a rotating vane--shake the IAC as you flush the inside of the IAC. If it's just dirty, then reistalling it will bring back a steady, normal idle. If it's too worn, then you'll have to replace it.
Dan
They are usually easy to remove--then flush/squirt solvent inside of it where there will be a rotating vane--shake the IAC as you flush the inside of the IAC. If it's just dirty, then reistalling it will bring back a steady, normal idle. If it's too worn, then you'll have to replace it.
Dan
