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 😐

[Big Moose]

Sounds like VATS wasn't removed

[Bobbyh68]

That’s what I’m thinking. Do the VATS cut off the signals to the injectors?
Noticed something else, with key in the on position the throttle plate moves when I step on gas pedal. So I believe they are communicating with each other.
The only code my scanner finds is p0622. That’s b/c the serpentine belt is removed.

[BR3W CITY]

VATS will immediately kill the motor on startup. At most it'll idle for a second or so.

If you told your tuner about the issue and he asked you to get a new computer....then I'm immediately curious about the tuner.

For the record; A BAD ECM IS AN EXTREMELY RARE FAULT. I've seen a number of threads on here involving online tuners claiming the user had a bad ECM. GenIII-GenV ECMS (all of the differents ones, 411, E38, E40 etc) don't have any major failure conditions. The 2 most known issues directly related to the PCM are internal case grounding issues (solved by grounding the case or actually repairing the internal ground), and the injector driver burning out.

I suppose you don't have copies of a tune or log file to look at? Its extremely easy to check if VATS has been left in.

[Bobbyh68]

Thanks BR3W, I don't have a copy of the tunes file. On a side note I removed the Computer from my other LS swapped truck that's 2005 DBC and the engine ran!! But with a high idle and of course no throttle control. I'm going to find someone local with HP tuners. I will definitely keep you posted.
Thanks again for your 2 cents! I really appreciate your help!

[Bobbyh68]

I got someone to double check my reflashed computer. My original programmer left the vats enabled! Glad you guys helped me, I’m up and running! Thanks.