Old VP44 finally died last week on the side of the road after about 5 months of dead pedal........ put a a bosch remanufactured from Thoroughbred Diesel in over the weekend. Immediately getting a dead pedal, not all the time but half of the time, mostly after its been warmed up. Also, truck will not start hot, have to pull the fuse out of the FASS pump for a hot start.

I'm almost 100% sure I was sold a junk injection pump....... they are giving me the run around. 1 guy said its my ECM causing it, which I dont believe because I did not have a hard hot start before the new pump, and today another guy from Thoroughbred is telling me my fuel pressure is too high, causing both symptoms. Fuel pressure is about 18-19 idle, 13 wide open throttle.

Any ideas guys? Am I just getting the run around?

 

Fass has been known to cause to high of fuel pressure, and if disconnecting the fuse corrects the problem then that is the cause now, your can try to relearn the dead pedal with a APPS Relearn which what you do is diconect both BATTs and turn the key on to accessories and let it sit for 30-60 minutes. Then turn the key to off reconnect batt, and then turn the key back on the ACESSORIES and push the accelerator pedal all the way down SLOWLY!!! and the release SLOWLY and then turn key off and you have Relearned your APPS and this can correct the dead pedal issue.

 

If you would like to you can lower the pressure down by cutting a single coil off the spring that should drop it down to 16 psi but 18 psi is a perfect pressure. Just make sure when you are running the system you do not go below 10 psi.

 

An APPS reset, and relearn are very cheap things to try that may correct the problem.

How old is your pressure regulating valve in the return port of the VP? Again, a cheap thing to replace that may solve the issue.

There shouldn't be power going to the FASS after the first second of the key being on. If it is, there may be a wiring issue or controller issue.

 

Below is the APPS reset procedure....