First time posting but I’ve reading and gaining from this site for quite some time . Thus the title of this post. I’m really struggling with my truck and I’ve read just as much as I possibly can. My background (just so no one is afraid to through anything complicated at me) is 10 years of diagnosing and repairing medium and heavy duty trucks and now about to reach my 5th year of being a shop manager.

 

Sorry this might be long winded. My 99 is a fairly new purchase and it wasn’t acting up when I got but now it’s getting terrible.

 

The two main issues are : when I first leave my house and start driving it will (only once or twice) loose power but it’s not the same dead pedal every one else describes. The truck doesn’t die and will rev up in response to throttle input. It’s just very low power and slow to respond. After it works that hiccup out I’m fine for a bit but eventually the truck does start dying . And yet again it’s nothing like I’ve read about. It’s a standard so with it still in gear and rolling down the highway, literally all I have to do is cycle the key and it’s rolling on full power like nothing happened. It has never not come back to life and when it happens somewhere where I do have to restart it, it fires instantly back up. Everything I’ve read says it dies completely or is incredibly difficult to restart . I’ve checked just about everything that I know of or have read about. I installed new batteries due to one of mine actually being bad. No change. Trying to be lazy and hoping it was something simple I changed the apps. No change.

 

The truck has never had a CEL. I even forced a CEL to make sure that part was functioning. The wait to start light functions completely normal. Sorry I’m bouncing around I just wanna to give as much info as I can .

 

Another thing is that while test driving it down the road to try and diagnose it with my scanner, as soon as the truck dies my scanner gets kicked out and says no communication. The scanner attempts to reconnect and if I cycle the key it reconnects and functions fine until the next time it dies. Also when running the scanner shows that the vp44 is claiming to only be getting 12.1-12.3 volts. I haven’t back probed it yet to test while running with a meter but I have unplugged the pump and checked the power and ground and it was within .01 of the batteries.

 

Sorry I know that’s a lot and there’s still more that Ive done but I know there are some very expienced people on here and hoping someone can help. That’s why I joined this one. Definitely a lot more info and a lot less “how do I roll coal” nonsense. 

Edited May 28, 20195 yr by Me78569

1 hour ago, Dieselinmyblood said:

Isolate literally everything accept the ecm and vp44 ? It’s a manual after all

 

No, not really. Being you need the PCM to start the CCD network. You need the ABS computer for road speed signal. Without the PCM you can't read any error codes from the OBDII port. Without the PCM the speedometer won't work and the grid heater won't cancel for road speed.

 

These are common issues with retro fitting 24V ISB Cummins. Once you isolate the ECM its a dumb computer and lots of other mods end up happening. Best to fix the existing problems that moding around the problem.

I have two second gens so a lot of bullet proofing gets done to both trucks. I just want to say that the G 100 ground was hidden on both mine. Hiding under a small bit of wire harness way down low in front of the drivers battery on the fender, but underneath a bit of that harness that it makes it like nothing is there, but is.

 

I'm into reliability and bullet proofing more so than anything else. Enjoy having a truck that everyone wonders how a museum piece can run for so long. I'm out to prove the best in reliability without buying a new truck. Just like my wife..... the older she gets the more I'm hooked on her.

16 hours ago, Mopar1973Man said:

 

No, not really. Being you need the PCM to start the CCD network. You need the ABS computer for road speed signal. Without the PCM you can't read any error codes from the OBDII port. Without the PCM the speedometer won't work and the grid heater won't cancel for road speed.

 

These are common issues with retro fitting 24V ISB Cummins. Once you isolate the ECM its a dumb computer and lots of other mods end up happening. Best to fix the existing problems that moding around the problem.

I’m not trying to do it permanently. I meant once it’s acting up I can flip a switch to send power where it needs to be and turn the ignition off so it isolates it to only the ecm and vp44. I’m not looking for codes since it hasn’t produced any, anyways and I have a gps to monitor speed . It’s just a test . If my issues go away I can start hunting wires or the pcm if they stay then it’s a pump or ecm . 

 

15 hours ago, JAG1 said:

I have two second gens so a lot of bullet proofing gets done to both trucks. I just want to say that the G 100 ground was hidden on both mine. Hiding under a small bit of wire harness way down low in front of the drivers battery on the fender, but underneath a bit of that harness that it makes it like nothing is there, but is.

 

I'm into reliability and bullet proofing more so than anything else. Enjoy having a truck that everyone wonders how a museum piece can run for so long. I'm out to prove the best in reliability without buying a new truck. Just like my wife..... the older she gets the more I'm hooked on her.

 

I actually found those grounds yesterday afternoon. 

Edited June 1, 20195 yr by Dieselinmyblood

10 hours ago, Dieselinmyblood said:

It’s just a test . If my issues go away I can start hunting wires or the pcm if they stay then it’s a pump or ecm . 

I'd give it a try.