Not sure whats going on. Starts fine when cold in the morning or afternoon when leaving work but right when the high idle engauges the truck dies. This just started about a week ago. I haven't changed anything except the oil and fuel filters, checked all the connections and not sure what keeps killing the motor. I run standyne fuel treatment and the air temps have been 30-75so I don't think gelling is a problem. Fuel psi is 20. XZT+ 3000 tune installed. Any ideas/help would be appreciated.

 

I would remove the Quadzilla and try it again. If the problem persists then I would check the leads from the VP44, and if that is not the problem, then I would suspect the bypass diaphragm has failed and when the timing is backed down for high idle you are losing injection pressure. If that happens it is time for a good rebuilt injection pump.

You may or may not get error codes if the pump is failing. But, you should get error codes if the wiring harness has problems.

 

Hey, thanks a ton for the info. I have not done anything w/the VP leads but I'll check and rule that out first. I'm guessing the bypass diaphragm is inside the IP? If so, then probably no sense in trying to just replace it....correct?