I have an 01 cummins, recently replaced the sending unit and the lift pump, now it will run for about thirty seconds then die. I reprime the system and it does the same thing. The only code is low boost pressure sensor. Had the truck in three shops, no one can figure it out.

 

might sound dumb..
anyone check the actual level in the tank?..maybe broke pipe in the pickup tube in the tank? can you pump 10-15 gallon out with the lift pump? you might have to bypass the normal wiring to test this. if you bypass the factory wiring to the pump how long does it run?

Fuel pressure?

-dkenny

 

If you worked on the truck & now have problems, check your work. Measure fuel pressure. You should have a gauge installed in the cab but at least check it at the VP test port.

If bleeding causes it to run, fuel is a problem. Check the entire fuel system from the tank to the injectors & also the return line. It may be something as simple as not replacing the copper washers at the banjo fitting or perhaps a leaking return line at the back of the head.

When mine was stock, lift pump would kick to 10# with key on then drop to 0. It would idle at 10# and go to 6# under load.

 

It has the Edge juice with attitude so i have gauges. Finally found the problem. New sending unit was reading wrong, at half a tank it was actually empty