1983 E-350 fuel delivery problem

I'm working on a 1983 Ford E-350 motorhome with about 60,000 actual miles.

460 cid, holley 4 bbl. (recent rebuild) with the infamous "stone" fuel filter.

2 factory fuel tanks with original fuel pumps

Factory tank switch under dash & switcher valve assy mounted in fuel rail.

Problem:

Intermittent fuel supply. Sometimes enough gas to run, sometimes not. (Stone filter is new and blows through freely.)

Please help:

1. I'm looking for an electrical schematic on the low oil pressure fuel pump shut off circuit; if indeed this model was equipped. (I know later 80's carbed 460's had this)

2. Schematic on the electric fuel switch / controller assy.

3. I know each tank has an electric fuel pump, but is there a 3rd electric fuel pump in the carburated 460?


My manual completely skips the 460 V-8 models. Thanks in advance.

We were having the same problem with the front fuel tank. It was easy to drop the tank (2 nuts to remove with hoses) and upon inspection the small hose on the fuel pump was clogged, Motorhome only has 10k miles on it. Also the bottom inside was rusted a bit and could cause blockage. The old pump had a filter that had long deteriorated due most likely to the age of the vehicle.