Hi Guys I need some help here. This is what I got. I put a 350 in the 92 Z28 I have.I used the tuned port set up off the 305 that was in the car .I installed 350 injectors and a 350 knock sensor.I have a zz4 camshaft in it.Pcm burnt me a chip for it. The problem is when I start it, it idles ok but surges until its warmed up.when after its warm I cant get the idle down it seems like its around 1500 the tach doesnt work well so its hard to tell. I have cleaned off the icm and reinstalled it. timing is on the mark and the car runs great just the idle is so high.The idle adjustment screw is all the way back and doesnt make contact so i cant adjust it there. Any help would be appreciated, Thanks guys !

 

Sounds like a vacuum leak or stuck iac. I would doubt the target idle vs coolant temp would be set so high.

 

btw, not sure if you are following the correct procedure to set the minimum idle speed setting with the iac commanded in.

 

I had sprayed staring fluid over the induction system and the idle didnt raise, and it seems like it idles fine when its cold.I am not sure how to set the idle speed? does it need reset in some way? I did have to egg out the bolt holes on the manifold to get it on but it seems like it is sealed and looked like the ports all matched up . Thanks for your help.

 

https://www.thirdgen.org/tpimod2
a scanner will allow you to see the target rpm and iac steps.

 

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where did you get the motor? I planning to do the upgrade also you any advice.