Hey guys, I really hope you can help me... I'm going nuts. I'm just at a loss...

1984 Corvette, 350 V8, Cross Fire Injection... 52k miles.

My daughter and I have basically reconditioned the engine... completely went through everything. Not going to share those videos because my focus is on getting it running and not sharing her channel. But we replaced the timing chain and nylon gears (they're aligned, and good), new gaskets... new harmonic balancer, set the timing to TDC, did all the things. The engine looks and runs pretty amazing, at least for a few seconds... and then it chokes.

Here's a video of what's happening:


Worth mentioning that I've tried disconnecting the timing adjust lead, doing it with or without, and as you can see in the video, the fuel pressure gauge shows full fuel pressure until the engine dies, and then I hear a click, and only seconds later, the fuel pressure drops quickly (part of a safety feature in the cross-fire injection system).

I'm getting a good cone fuel spray from both throttle bodies, and again, everything is basically new or replaced or rebuilt. The TBIs are both actually brand new... I bought one of the "service kits" that was left over from GM where it was a top plate with dual TBIs ready to go. I still replaced the gaskets in them, injectors are good, etc.

I'm getting spark, and fuel... and I think timing is decent.

I'm just kind of at a loss as to what's going on... really appreciate any help.

I've checked the codes, I get codes 34 and 42. I changed out the MAP sensor... pretty sure that's not the problem.

Any thoughts? Thank you!