01 cummins help

[jimmy]

I have a lady friend who has some trouble with a 2001 Dodge 3500 Duallie.
The truck will occasionally have periods where it will do little more than idle. This rarely happens but it has been going on for almost two years and the time between "fits" has been 4-5 months at times.
The lift pump has been changed 3 times, the pedal position sensor has been replaced, the fuel tank has been cleaned and inspected.
These things were done by different places, mostly Dodge dealers.
No dtc's were found when it has been in for repairs soon after the problem happened.

I drove the truck 3 weeks and it never occuured. I had fuel gauges monitoring the fuel pressure supplied to fuel filter inlet and the VP44 pump. I also dumped out fuel filter to see if there was water or any other contaminants in there. I turned it back over to her with the gauges mounted in view at back edge of hood (she is a school teacher and the guys at school thought the fuel gauges sticking up behind hood were SO COOL!! LOL) and it has finally had a few fits and the fuel pressure was fine. On the Dodges with factory lift pumps, the fuel pressure is around 10 psi and goes down as you load engine to 3-4 psi. When the fit occurred the fuel pressure would be 10 psi on both gauges (pre-filter and on the injection pump). She called me while it was doing it and I had here do a few things and nothing helped. The engine will not die and depending on severity it will have varying degrees of power above idle.
I was very suspicious of something in tank that is being sucked into pickup and obstructs it but I can't see fuel pressure at injector pump being high with throttle applied fully if that was the case.

Anyone have any ideas, or even better, have a TDS membership and can post for help?

My thoughts not yet investigated: does this injection system have a limp home mode and is that what is happening?
If so what can make it go into default mode?

Known cuases of loss of power on this range of Dodges is lift pump and pedal position sensor, both replaced...

I would think a problem with the VP44 injection pump would be progressive and would have worsened in the 45000 miles this has been happening.

If you think cummins has no troubles then I'll give you here phone number...


Thanks guys!

[weasel79]

I would have the vp44 checked out. I have had a couple on my service truck go out. It wouldnt stop running but just loose power while going down the road. As soon as I let off the throttle and get back on it, it would go ok. The certified cummins repair shop told me these have had numerous problems.
Just a thought. Maybe there is a way to check the inline pressure of the injectors one at a time.

[Deeregreen]

It does have a limp home mode, however, I don't believe it would switch in and out of that mode while running. Could it be an electical connection or loose fuse? I hate intermittent problems. Good Luck.

[thefermanator]

Check all of the connections first, but it could be the black box on the VP44 going south. The VP44 suffers from the same illness that branded GM's 6.5 as a junk diesel. The injection pump has some parameters built into it that are pre-set, idle and W.O.T. are 2 of them. If you had a CUMMINS breakout box you could test it further to see if either the ECM or VP44 is at fault.

[v8440]

Ensure that the alternator connections are tight-seriously. Not only the small wires and the big high current one, but the ground through the case itself. I'd remove it and clean it and the bracket off, while also checking the actual wire connections. Electrical noise from a bad connection at the alternator has caused more than one transmission to be torn down to fix the inexplicable shifting and tcc problems.

Electrical noise wreaks all sorts of havoc in those trucks from what I've read several times, and I wouldn't rule it out in this case.

*Edit* Lemme add to that-also remove all 4 battery terminals and clean each one. Then, do the same with the other end of the negative battery cable(s)-these are another common source of electrical noise.

[v8440]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: THEFERMANATOR</div><div class="ubbcode-body">Check all of the connections first, but it could be the black box on the VP44 going south. The VP44 suffers from the same illness that branded GM's 6.5 as a junk diesel. The injection pump has some parameters built into it that are pre-set, idle and W.O.T. are 2 of them. If you had a CUMMINS breakout box you could test it further to see if either the ECM or VP44 is at fault. </div></div>

I didn't know that the vp44 caused crankshafts and blocks to break, headgaskets to pop, etc. Ok, that was mean. Seriously though, what went wrong with the 6.5 that was the same as the vp44?

[jimmy]

The integrated module on the 6.5's failed and the VP44 has a module integrated onto pump cover but I am not aware of the VP44's module being problematic..
The pump is #1 on my list of suspicions but the randomness of this fault makes this thing a "throw parts at it" situation and the others that have worked on it have thrown all the cheap parts at it and even a not so cheap one (the pedal position sensor).
I am going to be looking at all the electrical connections on the pump.

[v8440]

Like I said, don't just check the ones at the pump. Check the alternator and battery cable connections (both ends of the cables).

[luckuslucas]

Does it throw any codes? Cycle the key on and off 3 times, then leave it in the run position. Any codes stored will show up on the odometer.

[thefermanator]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jimmy</div><div class="ubbcode-body">The integrated module on the 6.5's failed and the VP44 has a module integrated onto pump cover but I am not aware of the VP44's module being problematic..
</div></div>
The VP44's have the same issue with the module as the 6.5's, just not as severe as the 6.5's problems. One of the first tests that I've done for a no-start when hot is to pour water on the module and see if it re-starts.