'95 k2500 with high idle. 800 RPM with A/C, 1000 - 1100 without. Take a look at the injector stream, does the stream look normal.
[yt]I_ig1Fu9gCA[/yt]

[yt]Uv4EH2icLB0[/yt]




Thanks

 

Removed and cleaned IAC. Idle went to 1500. Whoops, forgot to plug into harness, idle dropped to 800 w/Air on. Makes me think the IAC works.

MAP, unplugged from harness, no change. Removed vacuum connection and idle went unstable until i plugged vacuum hose.

Looked for vacuum leak with carb cleaner.

High idle/ cold start diaphragm retracts at warm up.

next step is to look at fuel pressure, hope to find a port in engine bay. anyone know acceptable pressure range. Figure about 15psi.

 

As I search the interweb, hundreds of threads for high idle, no reports of success.

 

TPS checked? Maybe a TB cleaning?

 

TB cleaning yes, TPS check, not yet.