Sproadic Fuel Pump Issues and ECM? Need ideas.

[sgirt]

I swapped my engine several years ago to a 2001 Chevy 5.3 Vortec. No problems for over 20,000 miles. Out of the blue I started it and it shut itself off. Turned it back on not hearing the fuel pump prime. I thought the fuel pump had failed. Replaced it with a new fuel pump assembly from AutoZone for this engine.

The negative battery cable was unplugged while replacing the new fuel pump. After installation, it started right up and then shut off. No fuel pump again. I let it sit over night as I pondered what it might be. This morning, I went out turned the key, fuel pump primed and it is started then shut off. Again with no fuel pump.

I have no DTC's being reported from my software. I have verified the relay sending 12v to fuel pump with meter.

I am at a loss as to what it might be. Please any suggestions would be helpful. I can post a scan if anyone would find it helpful.

[93camaro_zzz]

I would monitor fuel pressure. A couple places like Autozone and Oreilly's will rent you a fuel pressure gauge for free. It almost sounds like it will prime the pump, but then, it will not operate after that.