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One has a 1986 Ford E-350 Cutaway, running a 460 cu. in. 7.5 Liter 4-Barrel Carburetor, for a 27 Foot RV that has been plagued with fuel pump and sender malfunction issues for four years. Finally, found the problem - power to the Electric Fuel Pump Relay, Passes Through the Oil Pressure Sender Unit on the Rear of the Block, and that had an Intermittent Connection. Hope this Helps.
Hey just circling back on this thread. I have an 84 E350 with the 460. It was running great on both tanks but somehow died over the winter. It will run perfectly on the rear tank but when switching to the front the engine dies. I have repeated this while driving a few times to see if there was air in the line, not luck. I am thinking it is the front fuel tanks pump or the switch. Is there a way to test the switch?
Don't discount the Fuel Selector Valve. As you can see, it determines + (positive 12v) electrical flows to the fuel pumps (and sender units), so it needs to work!
Don't discount the Fuel Selector Valve. As you can see, it determines + (positive 12v) electrical flows to the fuel pumps (and sender units), so it needs to work!
The fuel selector valve does not send power to the fuel pumps. The selector switch does that along with the tank selector relay.
The fuel selector valve switches the fuel gauge and aligns the tank fuel lines to the fuel line going to the engine.
Yes, sorry. Poor choice of words. I do realize there are two "selector" devices involved here. The tank selector relay is what I meant. The "system" in my older 1988 dual-tank works a bit differently, with a fuel selector valve that is a "passive" device, no electrical connections.
Check the fuses first (one fuse controls the pumps)
There was a recall on the selector valves
A rash of bad ones in the late 80's to early 90's
Start there and test power to both pumps (yes you will need to drop the tanks down to get at the wiring)
Unless you know the pumps are running how do you know how much pressure you have?
You would have to put power (jumper power to) on the wire (PK/BK) coming from the starter relay (solenoid) to test the pressure.
No, they will operate when the engine is cranking or if the key is on AND you have oil pressure.
Yes they should be available from a parts house like NAPA.
But it is unlikely that both fuel pumps are bad.
There is a bypass circuit that bypass the oil switch while cranking that is operated by the starter solenoid.
I think these fuel pumps are the same as the fuel pumps used in the 1986-1989 in-tank pumps on the FI trucks and vans. I took a fuel tank from a 1997 FI van and put the tank, pump and all in my 1992 E350 with a 4V Carb. and have been running it that way for 10 years with no problems.
I think they put out between 6-8 PSI as that is what the 4V Carb wants.
Here is a electrical diagram of the fuel system:
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Hello, I've been reading through as many conversations as I can find about the '84 E350. If possible, could the image that was with this article please be made available again? I am having a similar issue ( although mine doesn't completely start). I would like to gather as much information as I can. I would also love if I could have a schematic of the other two systems, just in case.
Thank you,
Hross