i just put in a LO5 in my 91 RS. everything works fine except for the idle. if i rev it and let off it seems that the idle drops to low then goes back up. and i think on the freeway if im getting off at an exit and im in fifth, when i put the clutch in to go to fourth the rpms drop so low that the car shuts off. could this be my IAC since it was dangling while the engine was out, and could of got dirty and now does not work well.

 

its just the idle speed?

you can adjust that - i remember i had to do that to my 305 once. instructions are in the tech articles

 

I had the same problem after my install to a 350 from a 305. I had installed a holley throttle body at the same time. I brought TPS voltage up a hair and adjusted up the Idle speed. That and it seemed to learn idle better as it broke in. Why would you leave your idle speed motor hanging ? Didn't it come off with the throttle body or plentum removal ?

 

the IAC was suppose to go into the intakes air cleaner houseing, but it was still connected to the wireing harness and just dangling away. any how it runs nice now, seems ot idle at 1000 when in open loop, and closed its at 500-600.

 

IAC is in the tb. and the IAT is the one it the breather