I just installed a new 305tpi stock into my 92 convertible. There is a new fuel pump and filter, new IAC, new distributor, wires, and plugs. I set the timing, IAC, and TPS per instructions. Car idles fine and runs fine except...any time when you initially hit the throttle the rpm falls before it catches. Once it catches it accelerates like it is supposed to. I was told by someone to replace the EPROM but I am tired of throwing parts at it. Has anyone had this same issue?

 

Check and make sure there is no vaccum leaks.

 

Sounds fuel related since you set the timing. Checking fuel pressure under a load. Might be a fuel pressure regulator or injectors. Sounds like Accel enrichment is lean .

 

We smoked it before we put the engine in. Noticed the throttle body had a slight leak around the seals. We will smoke it again on friday and I will look at the fuel pressure when the rpm's drop. If it was a lean/rich issue on accel what would be the fix for that?

 

I had your symptoms when truck was running rich x 4. Then with some reprogramming, richness went away.
The car on the other hand was rich x 3. A heated O2 (actually just a new one was all it needed) brought it to rich x 2.
If u can get a scanner or some way to see what the ECM is telling you that would be cool