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New member here.
my 01 cummins recently started acting up while driving. It seems like someone has just shut the fuel off for a millisecond or so. Sometimes even 2-3 seconds. I have put a guage on my outlet of my fass 150 and bumped the starter. I got 20psi. But I'm still unsure what running pressure may be. I haven't gotten any vp death codes. Could my ecm be shutting the fuel off intermittently for a split second. I'd like to wire an indicator light along with my glow shift presure gauge to let me know if the fass is shutting off bc of the pcm. I have properly reset the apps and contacted timbo, he says this dosnt sound like an apps problem. I can't drive the highway, all back roads. The other day I was able to do 70mph. How do I test the pcm to see if it's shutting off the fuel.
thank you.
Check for corrosion and/or loose connections on battery cables and major electrical junctions.
Test for alternator excessive AC voltage output. Easily done with a basic volt tester that reads in AC as well as DC.
I've had a bad lift pump connection do something similar to me. Worked ok when not running (bumping the starter), but would see my fuel pressure drop out while driving, and come back up. In my case, when the wire wore out, the lift pump shut down for good. When that happened, the injection pump got fuel starved and my engine then started running rough and bucking under load, but would idle ok.
Check over your lift pump wiring and connector closely and see if it is damaged. I also recommend a fuel pressure gauge in the cab so you can see what the pressure is while driving and under load. Static pressure checks from bumping the starter does not mean that your lift pump is good, need to see what it is at WOT to assess the lift pump properly.
The PCM does not control the fuel systems at all (unless it is a gas engine Ram). The Cummins ECM and VP44 control the fuel system on our diesel.
The nick on the black wire was from me snipping it to repair, before I thought to take a picture. For the lift pump, the black wire is the ground, yellow is positive. The yellow wire started to chafe over time and finally wore through, causing my problem.
