91 GT 3.1 Idle Speed?

[91GT]

Just bought a 91 GT (3.1, 5spd) from the original owner.

Car is clean and strong -- and completely stock -- but the idle seems a little low to me. When the engine is warm -- i.e. after I've driven it for a while, say a half-hour -- the idle is somewhere between 600-800 rpm and slightly ragged. (When I say "slightly", I mean slightly... it's not loping or stalling or missing, but definitely not as smooth as I would expect.) ÂÂÂ

Anyway, shouldn't the idle be higher than this? What is the stock idle speed for that engine/tranny combo?  (FYI, the car has 202,000km on it, and was always well maintained.)

Thanks in advance.

[Money pit Beretta]

Sounds ok to me. For a auto it should be around 750, for you I'd say around 600 at the lowest. The computer does try to look for the lowest idle speed and then will bump it back up before it dies. With that said it should not go up and down too much. I know it's hard to tell what's going on when you are looking at a stock tach. The idle air control could be going out, but you do have high km's.

[Mr. Beefy]

Sounds about right to me. Both my 90GT and my 88GT used to idle around 650-750rpm.

[SuzukiGhostRider]

750-800 rpm is stock idle. Check your IAC and TPS.