ClassA4x4

Just got back with my motorhome from a 2500 mile Baja trip and toward the last leg of the trip my Glowshift 3-in-1 showed 0 psi. My motorhome continued to run normal, no sign of fuel starvation. I was able to go over the I-8 grades from Tijuana/San Diego to Phoenix, going over 25 psi of boost and over 1100 degrees EGT.

Upon getting home, I substituted the gauge, fuel pressure sensor and wiring (I happen to have spares at home) - that did not solve the problem. Then, suspecting dirty Mexico diesel, I replaced the fuel filter/separator - that did not solve the problem either.

What could be wrong?

BILTIT

I would check with an actual mechanical gauge.

BearKiller

I only trust mechanical gauges.


That being said, it could very well be that your lift-pump has quit.

The VE injector-pump has an internal vane fuel-delivery pump that is capable of running the engine on a dead lift-pump with the driver being none the wiser.

However, with the lift-pump taken out of play, the high volume of cooling/lubing fuel that cycles through the return system can be drastically lessened, thus shortening the life of the injection-pump.

ClassA4x4

OK, so what are my options for a new lift pump?
1.stock (mechanical) pump, source please
2.Electric, brand/model and source please
3.???

BearKiller

The winner is behind DOOR #3 --- mechanical PISTON lift-pump Cummins part# 3936320 --- that number has been superceded a few times, but any decent Cummins parts-guy should be able to come up with it.


I never trust any electric pump as the sole source of motivation; most that use them are forever having issues with them.


HOWEVER, I do like an electric pump installed in a BYPASS line, such that it can be brought into play at the flip of a switch.

The beauty of an electric pump is that it can pump fuel when the engine is not running.

Very handy for purging and priming the system after any maintenance or in the event one forgets to switch tanks and runs the engine out of fuel.



As for the piston lift-pump, there is an excellent TECH write-up in our "stickies" at the top of our page.

BILTIT

Electric pumps are usually cheap enough that i always have a spare with me. no worries that way.