intermit high idle

[turbobusa69]

87 gn with stock ecm, recently after high boost pass it will stay around 2000rpm and not idle down. i was thinking bad tps so checked readjusted and doesnt seem to be that. i have scanmaster showing correct tps voltage for idle but still high idle. my next idea is bad IAC or maybe a loose throttle body blade. any other ideas? i have the good pcv with 1 way check valve so not thinking that but ??? also it will come down and have normal idle after abit but will do it again right after another 15-20psi or more boost pass.

what do you think

 

[bpman1234]

Have you checked all your hose for leaks also check for any thing that might be catching on the throttle like wires or hose . Really take a good look at the hose going to the vac block .what fpr do you have when I had a leak in the diaphragm it gave me a high idle what are your blms at ?

 

[turbobusa69]

nothing around linkage and closes correctly. maybe the vac block diaphram, was thinking it wouldnt idle down if it had a hard vac leak, but will check and didnt record the blms but will check next time i fire it up. thx

 

[bpman1234]

Check your headers also for cracks.