I purchased my first dodge cummins in December of last year. It is a 2001 3500 4x4 NV5600 with at the time 112,000 miles. I drove it 6 hours home without any hiccups other than the crappy steering which i have since fixed. In January i wrecked the truck coming off of a completely iced over hill and ran backwards into a rock wall doing 55+ mph. The truck drove home afterwards. Once i got it home and fixed the busted lights, the vp44 went out all at once and it died in the road. I install the upgraded thoroughbred diesel VP44, billet tappet cover, and a fass 165. My truck has not ran right since. It has a stutter now. When between 1700-2200 rpm it will randomly stutter almost like its cutting fuel for a split second. In the process of tracing down the problem i find out with my scanner that once my truck warms up to operating temp all my sensors go nuts. All sensor voltage, the ecm voltage, and the vp44 voltage will spike straight up and down repeatedly going from full voltage to no voltage until the truck cools off. I dont believe the 2 issues are completely related because the stutter is there even when the voltage trends are showing good. I have had multiple people look at it, spent countless hours testing voltages, moving grounds, hooking and unhooking stuff, and even sent my ecm off to be checked ($600) and can not come up with a solution. I want to love this truck so bad but i cant even remember what it was like to drive when it was doing good. Please someone help me diagnose my issue. I think at this point it could even be the fact that i am so deep in i could be overlooking the obvious. Just an fyi i have a fuel pressure gauge inline around 1.5’ before the vp44 that never drops at any point. It shows a constant 15 psi. I have tested the red/white wires from the pdc and all show almost 14 volts even when my scanner is showing dips. I doubt it had anything to do with it but my rear abs sensor is out. Havent got around to replacing yet. All the issues occur with or without the edge comp box. So far i have ran let the truck idle while watching the trend and unhooked my map sensor, abs module, and coolant sensor. Even with each or all unplugged the trend stays the same. I have taken alligator clip leads and ran grounds from each of the factory grounds to the frame, ran grounds from each of the factory grounds to the negative battery post, and hooked the negatives from both batteries together in the process of trying each factory ground. The trends seam to slightly respond when a new ground is hooked up but only for a couple seconds.

Edited 18 hours ago18 hr by Chickendog73
More info

Good documentation on your part for your initial post regarding this problem. You definitely need to figure this out - you have a good truck with low miles.

I don't know if you have a good wiring diagram for the engine controls, so I am posting a diagram below.

I suspect that the collision with the rock wall is related to your symptoms. A couple of questions, though:

• Did the "stutter" show up right after the collision, or after the VP44 replacement?

• How much time and miles elapsed between the collision and the VP44 replacement?

You mention testing the red / white wire from the PDC - I am assuming this is the wire that supplies power to the ECM and the injection pump. If so, I would continue to check voltage (engine running and voltage spikes occurring) downstream from there. As you can see in the wiring diagram, Joint Connector #2 (inside the PDC) and Splice #161 are part of that circuit.

I would also verify the condition of ground Splice 168 to Ground 125 on front of engine. If you are using another ground connection point with your test lead and there is truly a ground problem in the ECM / injection pump circuit ground, you will get a steady voltage reading because you are bypassing the potential ground fault. Also, I believe there is one more splice that is not shown in the diagram - that would be S109 that is between S168 and G125.

Are you familiar with the W-T ground reference modification? If so, has it been done?

• John

What is this w-t ground modification?

6 hours ago, Tractorman said:

I suspect that the collision with the rock wall is related to your symptoms. A couple of questions, though:

• Did the "stutter" show up right after the collision, or after the VP44 replacement?

• How much time and miles elapsed between the collision and the VP44 replacement?

You mention testing the red / white wire from the PDC - I am assuming this is the wire that supplies power to the ECM and the injection pump. If so, I would continue to check voltage (engine running and voltage spikes occurring) downstream from there. As you can see in the wiring diagram, Joint Connector #2 (inside the PDC) and Splice #161 are part of that circuit.

Are you familiar with the W-T ground reference modification? If so, has it been done?

• John

After the collision i limped it home. I was in shock (i spun around all the way off the hill and barely dodged going off a cliff, no pun intended). Due to the shock and just barely limping it home so i could get a look at the damage im really unsure if it started immediately at the time of the wreck. It also doesnt help any that the vp44 went out within a mile of my house after driving it the first time after the wreck. So they kinda happened simultaneously. The red and white wires in the PDC i mentioned are the ones you brought up that run voltage to the ecm and VP. Ive been doing all of my electrical testing when the truck is up to temperature so my trends are going crazy in an effort to be sure my testing stays consistent and to know the problem is actually there at that time. As far as the grounds go that was my intention with the ground leads. I was just trying to bypass any bad ground i could have to be sure that was not the problem. Like i said the trend seems to slightly react and smoothen out for a moment after hooking up the ground leads but then returns to what it was doing. As for the W-T ground mod i just found out about it the other day. That is my next attempt at this but at the moment im working 12 hour swing shift for the next couple weeks without a day off so it will be a minute before i can get that far. If it wasnt my daily driver i could do it after work but would hare to mess something up and have to borrow a vehicle for the next day.

34 minutes ago, Lund1990 said:

What is this w-t ground modification?

If you google it there are videos that show it. Its basically a way to “delete” the splices between grounds on these trucks. Supposedly helps with a/c noise and gives you better grounds where you need them from what i understand.

2 hours ago, Lund1990 said:

What is this w-t ground modification?

@Chickendog73 , how old are your batteries, and are they in good condition? How about the crossover cable?

• John

Edited 6 hours ago6 hr by Tractorman

Not sure on their age. They were in it when i got it. Thats something i can check when i get off work in the morning. Ive had no issues so far out of them as far as dying or having a hard time starting. As far as the cables everything looks ok.