6.0 Starts then Shuts off! Please help

[Bobbyh68]

First off I purchased a 2006 LQ4 / 4l80e DBW combo with harness and computer, only part missing was the TAC Module and pedal. I contacted the dealer for correct P/N and got lucky and found the correct pedal and TAC Module. Sent off my harness and computer to LT1 wiring.com for them to rewire and reflash my computer. Thought I was off to a good start, I’ve used them on my last LS swap. They do a beautiful job on the harness, just takes a long time.

Now after I received everything back from them and get everything hooked up. The drama begins, My engine starts and shuts off immediately. Checked fuel pressure, its at 62psi. Used a noide light on my injectors, they blink maybe twice and shut off. For some reason my computer is telling them to shut off. I contacted the company that refashed my computer and HE suggested I had a bad computer. So after purchasing a new computer and letting them reflash again. I have the EXACT same problem. Fires up and shuts down immediately. Could this guy be leaving the Vats enabled?

Can you guys point me in the right direction?
Could it be VAts, crank sensor ? IDK 😐