I drove my truck about 10 miles to town Saturday, it started and ran fine all the way there. Shut if off for about 10-15 minutes then no start. I left it and went back later in the afternoon. Still no start,
oil level good? Check
wait to start light illuminating? Check
​​​​​​ tach moving while cranking? Check
check engine light? No
I unplugged the ICP and it started and ran with a check engine light so I drove it home. It seemed to run ok, it just seemed to shift up at higher rpm’s.
Sunday, I plugged the ICP in and no start.
I unplugged it again and no start.
Today I tried it unplugged and no start, then I plugged it in and it started. No check engine light. It will start but has to spin a little longer than usual, idle seems normal.
I plugged in the OBD dongle to check codes and got P1280 injector control pressure failure. I cleared the codes and did it again and got nothing. Tried doing the the tests with Forescan and couldn’t get any of them to complete. They’ll go to 99% then back to 53% over and over.
Anyway, this is what the pics look like-
any ideas?

Idle

2k rpm

edit to add- injection pressure regulator, injection pressure sensor, crankshaft position sensor, engine wiring harness is all around a year old, all genuine FoMoCo from Riff Raff, the IDM is also a 1 year old rebuild from Chattanooga Diesel.
IPR nut is tight

 

I can’t get some of the tests on Forescan to run or they won’t run correctly, I’m beginning to suspect it could be a faulty ecm….

 

Very strange for sure. I don't have any fancy scan took like y'all have.

Your rpms are way higher on the one pic. Were you revving it or was that the idle?

 

one pic was idling, one was revving to 2k

 

Today, it fired up up just fine, drove it about 10 miles, shut it off and it fired right back up several times. Still having trouble with Forescan not reading codes correctly and the dashboard spids not connecting/monitoring. I’m still leaning toward PCM problems.
I’m going to pull it out and send to Chattanooga Diesel Technology for testing and/or possible replacement.

 

PCM relay contacts might be worn, swap it with one next to it and see if its better

 

I will try that Friday after the storm passes. I had not even considered a worn out relay as I’m completely out of ideas.

 

also unplug the bowl heater, they are known to short out and not blow the fuse yet make for fun with the PCM

 

Do you have a chip? Does it connect to the plug on the PCM? If so, check that the connection is clean, tight, and doesn't move. Not long after install, my chip got a bit loose and started driving the PCM nuts. Random shutoffs while running, randomly wouldn't restart. Pushed the chip firmly into connector, potted with liquid electrical tape, wrapped with tape so it couldn't wiggle loose. Years later and no problems. I've seen occasional reports here of similar events.

Is the main PCM connection tight and clean?

 

no chip. I haven’t had any more problems so, I haven’t done anything else. It has started right up every time, hot or cold.