'89 F250 with 460 fuel selector valve question

[scotts90ranger]

I have a coworker with a '89 F250, 460 auto

he claims to have blown through a couple low pressure in tank pumps, a couple relays and even shorted out an ECM. with the selector switch out he tested it with air pressure (through a regulator) and it was very sluggish in it's movement unless he turned up the pressure.

I remember AllanD mentioning a couple different types of fuel selector valves used by Ford and one being a lot better than the other, any help identifying what would be the best to get as they are apparently like $200...

also while I'm here, it's been sitting for a while, like a year and when he checked the tranny fluid it was high and leaking out of places higher than the fluid level should be, the truck had been through a flood but when he drained the fluid it was all tranny fluid, so he figured it drained out of the converter...

 

[AllanD]

Not so much a "Good" or "bad" valve as it is "different systems"

The '89 F-series will have a passive valve, passive because there is no direct user input to the selector valve, that "round" top is a diaphram housing
and whichever low pressure in-tank pump pressurizes
the chamber on it's side of the diaphram and the
valve, which has an internal detent pops one way or the other and both opens the ports to allow fuel flow
from the active tank and directs the treturn fuel to the same tank.

The usual problem is a leaky diaphram
which not only make the valve unreliable but allows fuel to bleed from one side of the system to the other.

Rangers use a purely active valve mechanically driven it does to the fuel lines what a double pole/double throw (center off) switch does to electricity.

On the later F-series there is NO selector valve at all!
Selection is accomplished inside the tank with a pressure driven valve that the active fuel pump opens to allow return fuel to that tank
the return and feed lines are simple "T" fittings

but these later F-series trucks also have a "Cannister"
inside the tank that not only houses this shuttle valve, but the returning fuel is run through a venturi
that sucks fuel from the tank into the cannister.

These had a problem with the check valve inside the pump that tended to leak and thus fuel in the unrestricted high pressure side would leak past the valve and into the inactive tank...
Can you say "uncommanded crossfeed"?

Ford's fix was to add another check valve inline to the outside of the tank unit.

Converting from any selection system to any other?
Lets just say that's a conversation I'm not looking forward to type into a keyboard unless I already have an advance from a publisher for a book I'm writing...

Your easiest course would be to aquire a new, stock
diaphram selector valve.

Converting an Early F-series to the late F-series system? I've done it twice and it is one of those things that was less than "fun"

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[scotts90ranger]

Thanks, I suggested he just get the new one...

 

[AllanD]

That'd be a plan...

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