Alright Ive been going around in circles with my 84 crossfire. The car has been having a hard time holding an idle, especially when its hot. The car also fell on its face under a load.

I found the fuel pressure was droping off, replaced the fuel pump. I pulled code 22 for TPS low voltage. The voltage was .23v, I set it to spec .52v at closed throttle. And I get 4.56 at full throttle. After I took it for a drive and it felt good, no problems for about 45 min of driving. Got home let it sit for a few minutes. Then it wouldnt start unless I kept my foot in the gas. No codes at this time. Anyone have any ideas????

 

All kinds of things can be hurting you. It's potentially a bad CTS (coolant temp sensor). The one to the ECM, not the one to the fan or the one to the gauge (they are all three different sensors on the '84). It can think the engine is cold even when it's hot, and richen the mixture accordingly which will make it not start when hot (too much fuel). Does it smell rich? Does it pass emmissions?

You should also check the TPS for smooth transitions. There shouldn't be any sharp bumps in the voltage curve from idle to full. It could be hitting a dead-spot somewhere off idle (not likely, but it's cheap to check).

It could be an IAC (idle air controller) sticking. They control the air passage for idle. If it's stuck too far open as the car warms up and the A/F leans out it could be not responding to the change. You can remove and very carefully clean them.

Now, falling on it's face under a load and not idling hot can also be caused by worn TB shafts (Throttle Body). When they wear, they develop an air leak that is sometimes constant and sometimes sporadic. You can check for this by looking for play in the butterflies with the air cleaner off. Also, with the air cleaner off you can use your fingers to cover each end of the throttle butterfly shaft on each TB. If the idle smoothes out with you covering the ends of each shaft, then there's an air leak there.

Frequently the crossfire cars are quite out of tune from years and years of neglect. You really should do a complete tuneup including plugs, wires, CTS (it's cheap), balance the TB's, and check the functionality of the EGR, TPS, IACs, etc. Frequently impossible problems end up being two simple problems you're trying to diagnose at the same time.

I'll assum when you said "fuel pressure was dropping off" you were measuring it under load. A WOT pass in 2nd gear will demonstrate the true nature of the fuel pump, but it means hooking up a gauge you can see while moving. Poor fuel pressure under load can cause very poor performance.

If you haven't already, look around the crossfire forum at http://crossfire.home-ip.net. Also do a search here for threads on crossfire tune-ups. I know there are several because I've started atleast a couple myself.