Something I'm sure plenty of you have dealt with, but after reading, and reading still no luck.
Here's what I'm dealing with.
https://www.dropbox.com/s/fyw1r47k06...%20PM.mov?dl=0

Rebuilt LQ9 with a PSI Conversions engine harness and supplied ECU. For reference, there's a single ignition wire that needs power while IGN On and Cranking. Since the new battery I bought has been worn down so much from starting, I parked my truck next to it, ran the ignition wire to the truck's battery so it has constant, good power, but no change in the issue.

Confirmed fuel pressure @ 60psi, power to the injectors, coils, spark plugs. It fires, but only for a second or two before it dies. My only guess at this point is maybe the ECU is cutting power to the spark after the first second or two. I've reached out to PSI Conversions and am just starting to get feedback from them on things to try.

 

Sounds like the anti theft is kicking in, that's what it does. It fires and then dies.

 

Replace your crank sensor

 

I've read that in other places, is there a way I can go about checking that? I downloaded EFI Live, but I've never used it. I'd probably have to order a USB to OBDII cable.

I did. I'm reading RPM signals during cranking.

 

I thought mine was vats related , started then died straight away.. On the 3rd crank sensor away it went

 

What brand of crank sensor? Mine wasn't giving any RPM readings until I swapped a new one. Now I'm getting RPM readings while it cranks.

 

I bought from gm , standard oem ...

 

this issue happen with me before after swap LQ9 to my truck , it start for second and die . if you have HP tuner just disable VAT and run it again ,
the ECU you got it have stock tune or been modified for your setup ????

 

I'm not up on all the specifics of the the vats, I knew more about it back in the day but it's been 10 years since I disabled a vats and I believe it's different depending on which pcm you're running. on some systems you can just wire in a resistor in the steering column wiring, others disable the vats in the PCM. Call some local tuners and see if they can tune it out for you.

 

Well I was able to get it running, but verrrrrry rough. I think some of the coils might be bad, as they're the only remaining original parts that came with the engine. I'm also getting trouble codes P0343 - Cam Position Sensor A Circuit High input, P0336 - Crank Sensor A circuit range/performance, and P0122 - TPS Sensor/Switch A Circuit low. All sensors are new. Trying to fire it back up again immediately after shutting it off seems to be hit or miss.

 

Are all grounds good? Ie, sensor grounds on engine harness to cylinder head, engine block to chassis.

 

Yeah all grounds have been checked, there's only a handful. After removing, inspecting, and reinstalling the crank sensor it now starts more often, but still runs very rough. I'm going to order a replacement.

 

There's a forum for diagnostic/tuning.............

 

And here he is.....