84 Carrera 3.2 occasional stall when warm

[jeffdannies]

Car was completely re-done by Cabell Restoration last summer so all new ICV,O2 sensor and was fitted with new Steve Wong chip to correct erratic idle issue. Generally starts up and runs strong but occasionally, when engine warmed up, seems to be more prevalent in hot weather, won't 'catch' upon decel to idle and will start cycling 200-800 rpm then eventually stall. Was going to have Rick Cabell possibly lean out mixture per some other posts. Any other thoughts?

[Chuck.H]

Hi Jeff, welcome (and post a pic!).

First thing I would check is the base idle speed - you can search here to find out how to do it, basically you use a jumper to disable the ICV and adjust the bypass screw at the base of the throttle body to get 800 RPM idle.

Second thing I'd check is that the idle switch is working, all the way to the DME.

Are you sure your ICV is working, ie when you cold-start do you see a fast idle above 1000 RPM?

Chuck.H
'89 TurboLookTarga, 359k miles

[jeffdannies]

Thanks Chuck, fast idle at start-up seems fine then settles at 800 rpm. Cycling/stalling problem most evident after engine up to temp and as mentioned when ambient temp in the 80's. Will pass along to mechanic your thoughts, appreciate them!

[rusnak]

Could be a vacuum leak. I would also check fuel pressure.