Fast Idle Issue

[93chevy]

I've got a 1993 Chevy K1500 4x4 manual transmision with a 5.7L carburetor engine that idles between 1500 and 1800 RPM's. I have adjusted the idle screw with a small response until the next time I start the truck. I was wondering where the best place to start would be?
Thanks

 

[nerfherder78]

Sounds like it is either a vacuum leak, or the throttle position sensor. Has it thrown any codes?

Idle on your truck is controlled by the computer and relies on information from the tps, so if its dirty, out of adjustment, or has failed it will affect idle speed.

To check for vacuum leak, turn the engine on and spray some carb cleaner around the base of the throttle body/intake manifold. If it stalls, you have a leak.

 

[93chevy]

Sounds like it is either a vacuum leak, or the throttle position sensor. Has it thrown any codes?

Idle on your truck is controlled by the computer and relies on information from the tps, so if its dirty, out of adjustment, or has failed it will affect idle speed.

To check for vacuum leak, turn the engine on and spray some carb cleaner around the base of the throttle body/intake manifold. If it stalls, you have a leak.

I check for a leak first and there was not one so I pulled the tps off and replaced that. There was also a house that belonged to a spider in there. I cleaned this out and replaced the tps which fixed the problem. Thanks for the advice nerfherder.