I have a 2000 Dodge 2500 w/ the 5.9 Cummings. My wife put gas in it shortly after the purchase and shortly afterwards the VP had to be replaced. I had trouble with the VP wiring harness coming lose when I stomped on it, so I put a plastic strap around it. I never had it come loose again. Coming home I went to pass another driver, pushed on the pedal and had what I thought was the same problem. Popped the hood and the strap was still good and the harness was tight. The truck will start after about 20 try's but will only Idle. I'm getting a P1689 Code and have checked the relay, fuses etc...I have also checked the wiring as per the "bluechip" site as to voltage and ground issues.

 

Did you swap the relay with another one and check? I would pull the harness of and check for loose or broken connectors and then go down the harness and look for any frayed, bare or broken wires. Which go to the ECM on the driver side of the block. But also I would check and see how the lift pump is also performing because it is the the main cause of malfunction/failure of the VP44 injection pump, The fuel filter will also cause restrictions of the lift pump to the injection pump.

 

The pump's not working so I guess it's either the pin connector or the pumps electronics. I'm getting around 12 PSI to the pump.

 

Only 12 at idle? should be 18-20 but thats an issue you need to correct. But its running at idle, which these pumps can do, but with no info from the ecm, it will not go past idle. Be nice to get an good OBDII and see what all the parameters are, but if you have had to use a strap to keep it tight it may have allowed enough vibrations to weaken a connection.

 

I had bad electronics, so if you get the P1689 code and your getting proper positive and negative feedback from your harness leading to the pump and fuel pressure from your lift pump and no fuel from the injector pump to the injectors, the computer has gone bad in the injector pump. The computer is cooled by the flow of fuel so I guess I'll increase the pressure from the lift pump.

 

Correct, Im sure its electronics, somewhere either the computer on the pump, or harness.

 

I had a bad injection pump with good electronics, so I replaced the computer and it now works. I'm surprised that I couldn't find anyone that had the same problem on line, hope this will save someone from the time and effort and maybe money.

 

Glad you got it fiqured out, did you fix the pressure issue from your Lift pump? IF it went that bad that fast that proabaly what did it..

 

Yeah that fixed it and I hope I save somebody time and money. The lift pump is a new raptor and it was getting around 16PSI so I bumped it up a little. I have not had a chance to look at the computer to see if It's a solder joint failure.

 

It's not a CUMMINGS