91 chevy s10

Why does it continue to idle high at stops?

More than likely there is a vacuum leak.

Assuming this is TBI, the possibilities include

  1. throttle plate sticking
  2. throttle position sensor bad
  3. temp sensor bad
  4. ignition timing too advanced
  5. a leaking injector

Is there any cloud of black smoke behind you?
Are there any other symptoms?
Any pinging on acceleration? Knocking?

How many miles are on it?
What engine?

I’m sure the others here will offer other ideas.

My vote is sticking IAC!

Yes there is black smoke, at times it seems to cut back, there is 225,000 miles on original motor, 4 cyl engine the E series fuel injected 1 barrel 5spd also the motor is LP gas compatible from Cananda but isnt hooked up. I have replaced the fuel injector, checked all hoses yet when I come to a stop the engine continues to run idled high about half wide open any thoughts or clues Id appreciate it because Im stumped.

Thank you thank you thank, it was the IAC but will definitely be getting rid of it soon. Thanks for the advice.

Kudos to Pete. Nice work.

And sincere thanks for the feedback.

Happy holiday to you and yours.

Woohoo! Thanks for letting us know! Happy New Year!