2001 vp44 crank no start

[Showey]

Need some help with this one.
2001 Ram 2500 5.9, 6 spd.
Pulled engine to reseal, reainstalled and reconnected and had a crank, no start condition. rechecked all power and grounds and ended up adding only power and ground to the VP44 and it starts. Reinstalled all circuits to the VP44 one at a time and the last one was pin 2, DATA+ and bam, no start again. No codes are stored. Has banks module and we pulled it from the system, no change. Reinstallled banks and all connections and no codes in ECM or banks module.
tested DATA + and DATA - for shorts or opens and even ran redundant circuits to the ECM. No change.Tested pump (sent out) passes. replaced pump anyway, no change. Sent out ECM for testing (passes) replaced ECM anyway (no change). backprobed DATA + and DATA - and have roughtly 2.5v on both sides with everything connected.
There is no voltage on pin 5 untill key is switched off (pass)
Disconnected center connector at PCM, no change. Limited data on scan tool shows nothing that would raise concern. tried withh all sensors disconnected anyway, no change.
Summery: Crank no start, all grounds are good and no codes are stored. Cut pin 2 (DATA+) to VP44 and it starts (and sets code P1689) and I have throttle response! I have not driven it yet because I am concerned about timing issues.
Please tell me SOMEONE has seen this before?

 

[Showey]

*BuMp*

 

[petersonj]

I am not sure that I can be of much help here. I would think the "crank, but no start" condition would be related to the removal and re-installation of the engine. If the engine ran fine before the removal, then I would focus my troubleshooting from the point of view that that something happened while performing the work and I would not replace any components.

Have you thoroughly inspected every wiring loom to be sure a loom was not damaged or pinched during the removal / installation process. A pinched harness can have a wire shorted to another wire - not necessarily shorted to ground. It could be very difficult to diagnose.

- John

 

[Showey]

Great advice and yes. Full insection, no pinched wires. I can ohm out the + and - data circuits and there are no shorts or opens. I feel the ECM is getting skewed information somewhere but unable to locate anything out of the ordinary when montering (limited) pids.

 

[Bromiley99]

Check your passenger side ground cable, one of them y’s and has two plug ins. One connects to a cable in the same loom as alternator wiring. Lot of important grounds definitely would keep it from starting.