VP44 might be bad

[jonathan1950]

So the other day my truck would not start.  When I turned on the key, the WTS light did not come on, then it would crank and crank and not fire.  I opened three injector lines, but no fuel was coming out of them as I cranked.  I finally used some starting fluid to get it running.  Two of the lines still did not have any fuel coming out of them and the truck was running rough.  I closed all the lines, reved the engine up and it finally started firing on all six.  I was able to drive it, even shut it off and restart it, but then a few days later when I tried to start it it would just crank with not fire.  I checked the voltage going into the VP44 and I do have voltage in what I think is the correct pin.  I am not getting any error codes, but am wondering if it might be the injection pump that is bad and not the electronics?  the reason for this is the fact that when I opened the fuel lines, even when running two of the lines did not have fuel squirting out of them.  Any thoughts of other things to check on before I replace the injection pump.  Also, I have taken out the auto trans and replaced it with a 5 speed, do I still need to use the S.O. injection pump?  I am not sure if I will gain anything as I do have 75 hp injectors, so it may be just as simple to stay with what I have?

[Mopar1973Man]

When I turned on the key, the WTS light did not come on

 

Sign of a bad ECM. WTS light should come on for a bulb check each time.

[jonathan1950]

My question is that if it is a bad pcm, then there should not be any power to the injection pump.  I read that if there is power to the injection pump then the truck will start and idle, but there would be no input signal from the pcm when I push on the throttle?  I did have to run the truck a couple hundred miles with 10 to 12 psi, so I am thinking that that caused the injection pump to sieze.  If the pcm is bad would that not throw a code or two?  If the injection pump is siezed but the electronics still good then it should not throw a code?  Getting it started and running with ether makes me suspect a bad injection pump also, but I am not positive and you may be correct that it might be a bad pcm and I am looking in the wrong place?

[hex0rz]

I've had to run my vp44 on 0 psi for months at a time before, still ticking with it!

[jonathan1950]

So even with no codes it could be the PCM?  I will have to see if I can find another PCM then.

[hex0rz]

ECM

[joecool911]

As I recall when I met you a few months ago, your truck took quite a while to start. So might be related to that symptom. Just thought I'd say hello and sorry you're having troubles.

[jonathan1950]

Thank you Joe, maybe it was the start of things?  It will get worked out, the truck has been running good so it will be worth getting it fixed no matter what it is.

[jonathan1950]

Does it matter if it is a five speed or auto ECM?  I am thinking not as it is for the engine and not the powertrain, but I looking at getting a used one and not sure if it needs to be the same that I have now or if any will work?

[hex0rz]

IIRC, it does matter.

[Mopar1973Man]

It any case the ECM has to be reflashed for your vehicle. Even buying a used one to make sure the correct software is installed.