Hi - trying to help my 82 year old Dad with a motorhome he's been trying to get fixed for over a year now. It's a 1983 460 Ford 350 Econoline 29 foot Rockwood motorhome. It starts and idles just fine...but after being driven a few minutes it shuts down as if getting no fuel. There have been 3 new fuel pumps put in it...the one currently in it is a low pressure hi volume pump that was told to us by a parts guy to be the one required. The "inertia switch" has also been "bypassed" in order to see if it was the culprit...but it still does it. Does any Ford expert out there have any ideas? My Dad would really like to see this thing running well, as everythign else in it is great. Several "backyard mechanics" have worked on it and done all they know to do. Any help is appreciated.
Christine

 

Few thoughts without actuall placing my paws on it. Since you have an inertia switch, I'll assume that the engine is fuel injected. Have you tried pulling some of the plugs as soon as it dies to see if they are actually wet? You could have a bad diaphram in the fuel pressure regulator causing the engine to load up with fuel and die. To check, pull the vaccumm line off of the fuel reulator to see if there is fuel in the line. If so, then the regulator is bad. I would also connect a gauge to the fuel rail's schrader valve to see what the fuel pressure is doing when running good and just as it dies. I would also follow the fuel line from the tank to the fuel rail for any hidden fuel filters. You could also have a bad ingition coil that is breaking down under load.

 

Christine,
Don't know if you ever got this fixed, but as I recall those beasts had a two pump system if they were fuel injected. The first pump being a low pressure "lift" pump in the fuel tank, and the second a high pressure fuel pump on the frame rail. The symptom you are describing is typical of a bad in tank pump. Both pumps share a common electrical circuit so only one fuse, relay and inertia switch.

 

We have the same motorhome but 1989 with the same problem, after trying so many things found when we pulled the gas tank off it was loaded with rust from sitting around. Had to get the tank cleaned and sealed.
Geoff

 

Looking for the service manual for a 1983 ford econoline motorhome - coachman