1995 Yukon High Idle

[strutaeng]

Vortec started in 1996.

All OP apparently knows is that his engine is a 5.7 350...

 

[east302]

Once your driving the rpms will shoot up to about 1500rpm if you put it in park. While driving at idle at a light or stop sign its around 800-1000rpm.

Is it happening only when the brakes are applied (brake booster)?

GM published diagnostic procedures in the manual. The link is in post #6, but here is an example from the 95 manual:

 

[GMCChevy]

At this point rather then continuing to throw psrts at it you should probably use a scan tool thst shows what the different sensors are reading so you can either pinpoint which one is bad or what reading isn't at a normal level.

 

[Steven94]

Is it happening only when the brakes are applied (brake booster)?

GM published diagnostic procedures in the manual. The link is in post #6, but here is an example from the 95 manual:

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High idle starts after driving low idle starts as soon as I turn it on but sometimes it’ll start to high idle after a few minutes warming up

 

[Steven94]

At this point rather then continuing to throw psrts at it you should probably use a scan tool thst shows what the different sensors are reading so you can either pinpoint which one is bad or what reading isn't at a normal level.

Waiting for it to come in