Hey guys got a question. I have a 7500 onan gen on my motorhome. It is powered by a 3 cyl cummins with a small p pump on it. Anyways what is happening is that it will run for a little bit and then quit. I started doing it qt blackout. When I got home I did a complete service in it (oil, filter, air filter, and fuel filter) seemed to work good at home but now I'm on the road again and it won't stay running again. Any ideas?

 

Air getting into the fuel line maybe ?

 

Mechanical or electric lift pump, or any at all?

Fuel shut off solenoid?

 

Sounds like fuel supply. Unless the controls are getting a wayward ESD signal.

 

No lift pump at all.. after I changed the fuel filter it seemed to work just awesome. Until I started driving,, then it just wont stay running. I dont think it has any electronics at all (if that helps) I definately think it is a fuel issue though for sure.

 

the fuel tank has crud in it as you drive it shakes up crud is ingested by filter as it is suspended in fuel .when you were at home and changed it all had the motor home had been sitting a few days ?
so wait till its parked twenty min or so change the filter and see what happens . or go and run it off a Jerry can to test it . you might have to prime it though

 

That makes sense,,, it seems to happen when the fuel tank gets to below 1/2 tank,,, the MH itself wont run if it gets down to 1/4 tank,,,,, crap that sucks

 

Hellman sump for the genset...

 

I think that there will be a brown mh on the lot in red deer next week. Frickin thing. Started it up this morning worked like a champ

 

parked all night not moving eh .there may be a drain valve and it could just be the accumulation of water and other crud over the years . drain it replace it see what happens but drive it for ten min or so over bumpy rds first. I have kid you not found a Bic pen cap in a fuel line came off as some one was writing a report on fuel level ,took three months before that one was figured out as it would be fine most of the time as the cap floated !!!!

 

My Second Year HD instructor told us about an experience he had with a Class 8 tractor. Same kind of idea, would stall when moving randomly for no reason.

He finally found a small piece of clear plastic wrap in the fuel tank, which would every once in a while block the pickup as it sloshed around the tank. It could not be seen floating in the fuel.