I have a 91 camaro rs, 305 TBI, 5 speed, pushing 200k (runs good though). The entire car is stock and having issues with an akward idle problem. It will idle just fine when it gets up to normal running temp, but eventually will idle around 2 grand after 10-15 minutes of driving. Sometimes it will fluctuate between curb idle and 2000-2500 rpm, but mostly hang around 2 grand. I was told that it could be an issue with the o2 sensor, the TBI system, the idle air control (which was replaced), a vacuum leak or a leak in or around the throttle body/intake. Also my tach reads high....for example: if curb idle was roughly 800 rpm the tach would read 1500 rpm, how does this get fixed? Is it electrical or tranny issues, or something else? Any suggestions would be very helpful and much appreciated.

 

Would not hurt to check the module in the distributor. I usually have one laying around and I prefer the GM ones.

 

I replaced the Throttle position sensor and that did the trick. It runs as good as it's going to get until I get a chance to overhaul the ignition system. The module will eventuallt get replaced. Ugh....so many sensors! thanks