I picked up a 2000 Ram 2500 with the Cummins a few months ago. The PO said that he'd replaced the fuel pump a couple of times, which I should have paid more attention to. Ran fine though for a few months. Recently I had a big miss, or shudder under heavy acceleration onto a highway but ran fine for the rest of the trip. It happened several more times on later trips, usually at gradual acceleration. No CEL at that time. I did get the 0237 code, so got a new MAP sensor hoping that would fix it, but it didn't. I cleaned all grounds and harness connectors. Since then, a few test drives have been OK, with no missing, but even though I cleared the codes, they come back.

I have AutoEnginuity, so got the Chrysler enhancement package and found a few things. The MAP sensor checks out with 5.2V key on engine off. Test run yesterday, backing out of the driveway the voltage dropped to 4.93 briefly. Once going down the road, it stayed above 5V and responded seemingly correctly to acceleration. I suppose that the brief drop below 5V would be enough to throw a code. Let me know if otherwise. I haven't tried bending the diaphragm yet as described in a HOW TO DIAGNOSE VP44 FUEL SYSTEM ISSUES document.

Another thing I noticed was that the VP44 input voltage was dropping from 12.18V down to ~9V. Occasionally it would jump up to 13.5V, which is what I was measuring at the battery when it was running and the alternator was charging. 12.18V was what the battery read before starting. They were brief excursions either way, but it got progressively more frequent going down to 9V as my test drive went on. I can log and provide these charts.

The Banks tuner was unplugged during my testing, but was plugged in when I first started having the miss/shudder issue.

I thought I might be in limp mode, but I was getting boost pressures of 5-8 psi with just moderate acceleration on a test drive yesterday. Didn't feel too bad.

Try find one that shows the voltage of the PSG.

I'm not sure but some of those seem like they would be simple logic answers being true/false or 1/0 responses.

Edited December 8Dec 8 by Mopar1973Man

No progress yet. Here's a video showing minor sputtering around 10-13 sec, and then major from 20-25 sec. The shaking is just from the miss. Typical road bumps all other times. Log at the same time showed no red flags at those events.

https://drive.google.com/file/d/1E14BZAQJ3RQUKvTiRCBajmeTOiAcBrsw/view?usp=sharing

Edited Friday at 06:33 PM2 days by timsch

Thanks for posting video. That is definitely all cylinders cutting out - like the fuel is briefly shut off intermittently.

I watched your video a few times. Couple of questions.

• Just before the first cut out, your tach increased in RPM's. Was that you pressing the throttle or did that happen on its own?

• Can you make it happen? If so, exactly how do you make it happen?

We gotta get this fixed!

• John

Yes, that's me giving it the throttle. I can ease it up to speed, but any greater acceleration and it starts cutting or bucking. The more throttle, the more likely it's bucking. And it's consistent now.

Thanks for sticking with me John.

Edit: One thing I keep going back to in my mind is that the PO said he'd replaced the fuel pump a couple of times. So, a couple of possibilities: either something in my system may killing these pumps, or I'm dealing with a reman pump of not good quality that's failing. I recall reading on the forums that there are recommended rebuilders and you don't want to go cheap on that.

Edited yesterday at 12:36 PM1 day by timsch