I just purchased an 84 crossfire injection and it has a very choppy idle. It is steady for a while then goes down and up then back again. I dont know much about electronics. any suggestions. Thanks guys.

 

Cross fires were notorious for vacuum leaks on the upper plenum gasket. With the engine idling, spray a little snort of carb spray around the edges of the plenum to see if the idle changes. If it does, then you have found a vacuum leak which will cause idle instability. [8D]

 

Mech259 is th cats a$$. I know I've learned alot from him.

 

Thanks! The plenum gasket was leaking. Now I have found that the gasket at the base of the injecters and the air cleaner gaskets are leaking as well. Replacing today. Will let you know the results.

 

Glad you found it. Remember to disconnect your battery so your car can idle relearn. Disconnect it while you are working on it, then after the job is finished, go drive it for a bit so it can relearn idle posistion.[8D]