Gen 4 5.3 ls swap no start

[sprint_9]

Hi, I have a 72 c10 Ive been trying to get up and going and havent been having much luck with it. It is a Gen 4 5.3 that was a new crate motor, BP Automotive swap harness, 4l60e.

The issue I have is for whatever reason the ecm will not cycle the ground for the injectors or the coils. I have checked the pink wire on one coil and one injector and have 12 volts, and 10.5 while cranking. I never get spark or a noid light to light up. Ive checked stationary grounds on a couple other sensors for a ground to the ecm and I do have a ground to the ecm and back to the battery. I checked the fuses in the fuse block and all were good.

The one thing I am unsure on is my ECM. I wanted an ecm for a 5.3 and was sent one for a 6.0, from a yard. I compared with a 5.3 file within hptuners and copied the differences, turned off vats, starter checks, and displacement on demand. I enabled speed density as I have a corvette MAF and I was unsure how that would affect things off the start, although Ive tried starting it both ways with no change.

Im starting to suspect my ecm being for a 6.0 is the problem, or the ecm is bad, I dont know. I was wondering if anyone had any suggestions.

The only two codes Ive had.

0x7E8: P0463 - Fuel Level Sensor A Circuit High (Pending, Current, Old)
0x7E8: P0615 - Starter Relay Circuit (History)

[blindsquirrel]

What ECM are you using, and is the motor a 58x or 24x?

[sprint_9]

E38, 58x

[5FDP]

Did you do a write entire for the VATS?

[sprint_9]

Yes

[sprint_9]

I was able to log onto a 2011 truck with a 5.3, more or less the same setup I have but in a stock vehicle. I compared the scan results when cranking and found no differences other than one thing. My swap shows absolute load at 28%, the 2011 shows 0. Think that makes a difference?