LB87FORMULA

iTrader: (3)

I've had new engine in my 87 Formula for over a year. Unfortunately, when I over heated my 305 and cracked the heads, I didn't know about Thirdgen.org, otherwise I would have put in a different engine and cam myself. The engine is ok but the people who put it in were extremely careless.
The engine overall runs great, no heasitation at launch and much more powerful than the 305. I've fixed numerous problems with the engine swap including wrong timing, loose runner bolts, broken egr vacum lines, hanging air pump, missing bolts, etc.
The only thing I have left is a rough and surging idle that starts high and creeps down. TTS Datamaster shows my IAC counts to 0 which indicates a vacum leak.
Can the intake manifold be installed incorrectly to cause this type of vacum leak or possilbly the valves be adjusted wrong? I'd like to fix this problem before I replace the heads.

Quick_Trans_Am

iTrader: (2)

I would inspect all your vacuum lines, etc. before going that extreme. Check your IAC valve too, it may be sticking and in need of a cleaning, or it may be out of adjustment.



https://www.thirdgen.org/newdesign/tech/tpimod2.shtml


This link should tell you all you need to know on adjusting it. Good luck, and hope it helps.

LB87FORMULA

iTrader: (3)

Thanks,
I actually did that a couple times. I just ripped off the valve covers and adjusted the rocker arms. They all seemed about a half turn loose. I hope this improves the rough idle.