I do need to re-check my grounds. I've eliminated the problematic ground connecters on the large cables below the battery box years ago. I also checked alt voltage at idle...it's consistant at 13.8.

 

My mistake. Pin 7 at the VP is powered from the fuel pump relay from the power distribution center pin 87. Maybe you could tap a test indicator light in. That would be cheap and easy.

I knew the data link wouldn't power the friking pump too.

 

Could this also be described as the dead pedal syndrome?

 

No dead petal, it responds perfectly.
OK, I just finished pulling and cleaning the IP electrical connector. No change. I then added 4 test wires and 2 jumper cables bypassing all the engine and battery grounds...no change

 

Nmen, I don't know if there is a bosch dealer nearby. There is Los Angeles Cummins, but don't want a repair bill greater than the value of the truck.

 

Could the Edge be causing it? Have you unplugged it and run the truck without it? --nevermind--I re-read your first post...sorry

 

No change meaning the Pin 7 at the IP had a dedicated 12VDC and it still had the anomaly?

If so, it is a strong case for being internal at the VP.

I'm thinking tap the wire parallel with a test light -that is PIN 7 @ VP44 to the PIN 87 @ PDC, and you probably won't see it go out then when the phantom came back.

 

I'll try monitoring the power wire to the IP in the morning. If not, guess I'll punt and take it to Cummin$

 

There is the relay that charges that line, perhaps it is going bad. Easy fix then. Let us know the outcome.

 

Pull the connector at the pump. Find the pins(on the pump side)where the red and black wires go in. Hook jumpers to the pins, red to battery hot, black to battery ground. The truck will start and idle. It won't rev, and it will likely set the CEL, but it will be isolated from the rest of the electrical system. If it misses now, you'll know it's an internal pump problem. HTH . BTW, there is a tool made for this(it performs several other functions as well), but I wouldn't think it was needed for this.

 

I have reread all the test you've done. Conclusion is VP44 is trying to die due to electronics in pump itself. The failure is so short and erratic that a code does't set. Cummins dealer is gonna take a long and expensive look and finally say the VP44 needs replacing.

 

Well, I unplugged the IP and jumped power and ground to the red & black pins. Truck started and idled but started to stumble right away. So the problem is on the IP side. I ordered a rebuilt IP from Thoroughbred diesel today.

 

Sorry to hear it. Thanks for the update.

 

Got the pump on and it fixed the problem. So it is possible to have bad electronics on the IP without setting a code. Thanks to all that replied.

Changing the pump was not too bad except getting a gear puller between the radiator and the engine. Was pretty hard starting and i thought I'd done something wrong, but finally cleared. Now runs great.

 

"Pull the connector at the pump. Find the pins(on the pump side)where the red and black wires go in. Hook jumpers to the pins, red to battery hot, black to battery ground. The truck will start and idle"

If the only inputs to the VP44 are the power and ground and there is no data signal or crank signal, then how would the pump know when to inject the fuel? I don't see how the engine could run, even just at idle, without some kind of crank signal, TDC signal or something like that.