Need help troubleshooting an '06 sierra for 1st startup

[eberhama]

Building an '06 sierra 2500, its a junkyard refugee(I work at a salvage yard).The body, ecm, bcm, speedo, column, and dash harness are off the '06 sierra. The motor, the associated sensors, and the engine harness are off an '06 Silverado. All the plugs and fuse panel were the same, so I know that's not the problem. I've got the truck together enough to try to start it. The first time I hit the key, it started and ran for about 2 seconds and shut off. When I tried cranking after that, it makes the fuh-fuh-fuh sound(technical term) like it wants to start, but doesn't. I've got good pressure at the fuel rail, and the fuel pump is running. There isn't a security light on, so I don't think its the security. One thing is the motor has been sitting for 5 years, is it possible the injectors are stuck shut? is there some kind of re-learn I need to go through? any thing else I might be missing? The motor spins nice and is clean as a whistle inside. Also, plugs are clean and dry...seems to point to lack of fuel???

[96/chevy/pu]

Well that would be a good guess, but would help if you had a scanner to see whats going on.

[Frenchy]

Vats

[TXSZ66AVLANCHE]

Fuel enable signal not recieved from bcm= crank relearn needed

[Ray@NP]

Any DTC's

[farmtruc]

Fuel enable signal not recieved from bcm= crank relearn needed

Crank relearn is performed while the engine is running. It will not keep the engine from running.
Even tho u have all the parts so vats won't interfere. It still sounds like vats is messing with it.
Like he said. Dtc?

[eberhama]

Just a little update...I borrowed a snap-on modus scanner from work. The only codes it was showing were two about a heater control circuit voltage low or something. I forgot to mention that when I first had everything hooked up, there was a Jet performance chip thing on the ECM. At that time, the motor would just crank and crank, with no fire at all. I pulled it of, and that was when it ran for a few seconds. Is something in the ecm changed or reflashed when the chip is added? I can swap a diffrent ecm with the same p/n, any idea if that would make a difference? any other suggestions??

[eberhama]

Any ideas or suggestions before I bring the scanner back?

[TXSZ66AVLANCHE]

In the live data area of the scanner look for "Fuel VTD Enabled" if "yes" try and crank the truck and leave key on, look at same live data and see if the VTD timer is active.

[eberhama]

Sorry for taking so long between posts...life keeps getting in the way. I'm not seeing the live data area on the scanner? any idea what it would be under? I did notice it says under engine data, "current gear: 2". when I plug it into my '05 1500, it says "current gear: 1" when they're both in park. could I have gotten the neutral safety switch on wrong and thats whats f'ing me up?