Guys, I'm just done.
I've swapped three different AFMs and three different ECUs. Gone back to stock ignition components (coil, ballast, amp, plug wires), replaced every sensor and wiring, checked continuity for everything at the ECU harness, replaced gaskets and seals, checked injectors and wiring, compression, battery, etc. I've literally gone step by step through the L-Jet tuneup guide no fewer that four times in the past two weeks alone. None of it does any good because the car either won't start, or will run beautifully for 30 seconds then abruptly shut off. The ONE thing I haven't replaced is the distributor.
I'm just at a complete loss. This problem is clearly beyond my capacity to solve, and my wife is just angry thinking about spending more money on it. I think I have to part it out or sell it outright. It's been problematic from the day I got it, with random and dangerous shut-downs. Every time I think I solve it, the problem reappears, but slightly different. Instead of an immediate switch off, it'll choke out. Instead of choking out it'll begin missing violently. Instead of missing violently it'll shut off, like originally.
Ugh. This car is cursed and I just can't contain my frustration with it.
as good as a car can be... briefly.