my 87 Iroc (51k miles) is idling at about 750 rpms. When she's cold (and I think even last summer when it was hot) would drop to 500rpms and then stall out.


I don't drive it much, so I'm thinking something is gumed up. Fuel filter was changed when I bought the car ~9 years ago, but less than 10k miles.

I changed the IAC valve yesterday, no help.

i really don't want to keep throwing parts at this, since it'll go back into storage here in a week or less.

i can't seem to convince myself it's the TPS as the throttle response is spot on, but the rpms (750) seems low to me?

I haven't driven it enough to remember what it normally was, all of my other cars are around 1,000.

 

My car idles at 650 fully warmed up. 900 it's first started. I'm betting the gas is bad since you barely drive it.

 

I always keep Sta-bil in the gas.

Last summer I drove it enough to run a few tanks of good gas in it (always 93) and still had the same problem.

EGR? TPS?

 

clean the throttle body.

 

Possible bad pick up coil. You can test the TPS with out buying one first, you never know, tpi for some reason is very unexpected, you think its one thing.... when its actually the opposite, or another part. Mine idles at 1000-900 cold, and 600 rpm warm, 650 with the ac running.