1999 Holiday Rambler won't start when hot. Quick fix!

[beetle90210]

I have been in a dilemma for a while because I have been thinking I might have to replace my vp44 injector pump. Turns out it's weak, and the lift pump is putting to much pressure to it on start up. This is what I did:

I have recently had this problem with my 1999 Holiday Rambler, with cummins 275. The injector pump seems to be weak, and to check that, I momentarily unplugged the lift pump upon starting. It started right up. The injector pump is letting to much fuel through when hot. Each time I tried with the lift pump active on start up, the engine would just spin over like it was starving for fuel. Apparently it is just the opposite. When I unplug it, the engine cranks right up. Of course I had help with this operation, as it started and I immediately plugged the lift pump back in. Now.... I picked up a normally closed relay and installed it at the lift pump to shut it off during the cranking process. I hooked it up to the starter solenoid for the temporary power to shut off the lift pump with the solenoid. So far works fine.
Now I don't know how long this will keep me going, but it is a cheap fix instead of replacing my vp44.
The relay is just a generic one I picked up at the local napa store. It is a kit with the relay, and the receptical with shot wires to solder to.
Hope this helps, I know it did me!
If anyone is having this problem, I recommend this test.

[Ivylog]

VERY INTERESTING!!! Doubt I would have thought to unplug the lift pump. Did it start alright when cold???
Not sure why this got moved to the Monaco section as may MHs have a Cummins engine.

[beetle90210]

Yes, it starts fine when cold. Just like there has never been a problem. The relay did the trick. After reading several threads in the “Cummins forum, I learned that this pimp(vp44) actually works better on start up with 0 pressure. Anyway, it’s working fine at this point.
Chuck