Fuel Exchanger Help!!
Thread Starter
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Senior User
Joined: Dec 2007
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Fuel Exchanger Help!!
I need to know if I can just bypass the dang fuel exchanger with new fuel lines. It wont switch to the rear tank and I dont know why. WHen I flip the switch it just keep sucking from front tank. If you unhook the switch it defaults to front tank. I got a full rear tank and empty front. Lost I dont even know where to begin.
Posting Guru
Joined: Jan 2002
Posts: 1,346
Likes: 8
From: Baltimore
Sounds like the rear in tank pump is bad. The tank selector valve is mechanical and
is switched by pressure. If the rear pump is bad, the selector valve won't switch and the pump on the driverside frame will pull fuel from the front tank.
If you think the selector valve is bad, it's availble from Ford for around
$70.00
Here's the schematic for an 88. 89 should be the same.
When you press the tank selector switch on the dash you switch power
to the in tank pump and the fuel gage.
is switched by pressure. If the rear pump is bad, the selector valve won't switch and the pump on the driverside frame will pull fuel from the front tank.
If you think the selector valve is bad, it's availble from Ford for around
$70.00
Here's the schematic for an 88. 89 should be the same.
When you press the tank selector switch on the dash you switch power
to the in tank pump and the fuel gage.
Thread Starter
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Senior User
Joined: Dec 2007
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Ahh I get it now. When you flip the switch it cuts power from front pump and shifts it to the rear pump. Rear tank pump is bad and it wont pressurize the selector valve thus engine runs out of fuel.
Next question...
Could it be the fuel pump relay or are they on the same one? To check the rear pump just flip switch to the rear pump and listen for the rear pump?
Next question...
Could it be the fuel pump relay or are they on the same one? To check the rear pump just flip switch to the rear pump and listen for the rear pump?
Posting Guru
Joined: Jan 2002
Posts: 1,346
Likes: 8
From: Baltimore
All 3 fuel pumps get 12 volts from the same relay.
Under the hood driver side black plastic wheel well is the diag./test connector.
One of the pins is a Tan/Light Green wire. If you ground that pin/wire and turn
the ignition switch to on (no need to start the engine) the selected in tank pump
should run along with the frame mounted pump.
Here's a pic. of the VIP test connector. It's the pic. top far right.
run.
Under the hood driver side black plastic wheel well is the diag./test connector.
One of the pins is a Tan/Light Green wire. If you ground that pin/wire and turn
the ignition switch to on (no need to start the engine) the selected in tank pump
should run along with the frame mounted pump.
Here's a pic. of the VIP test connector. It's the pic. top far right.
run.
Thread Starter
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Senior User
Joined: Dec 2007
Posts: 174
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Trending Topics
Senior User
Joined: Jun 2006
Posts: 388
Likes: 1
From: Murfreesboro, TN
Is this fule exchangfer (selector valve) still available from the Ford dealer? If not where? Link please...
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Posting Guru
Joined: Jan 2002
Posts: 1,346
Likes: 8
From: Baltimore
Here's the part number for the selector valve used on an 88 gas engine. Call the dealer to verify it fits your vehicle and if it's still available.
https://www.ford-trucks.com/forums/3...light=selector
https://www.ford-trucks.com/forums/3...light=selector