1988 Ford F250 6Cyl With 2 Fuel Tanks! When running on front tank it puts pressure in tank and comes out fuel cap.Can anyone help me out.

 

Robert DiCarlo,

Bad selector valve on the frame.

 

THANK YOU1 subford

 

I see a 1989 f250 recall for a fuel selector valve:

September 30th, 1991
Recalled Component FUEL SYSTEM, GASOLINE:STORAGE:AUXILLARY TANK:SELECTOR DEVICES
Recall Date September 30th, 1991
Units Effected 350,000
NHTSA Campaign Number 91V146000
Manufacturer FORD MOTOR COMPANY
Manufactured Begin Date February 1st, 1989
Manufactured End Date February 1st, 1991
Date of Owner Notification December 20th, 1991
Defect Summary:
THE DUAL FUEL TANK SELECTOR VALVE MAY MALFUNCTION AND CAUSE AN OVERFILL CONDITION IN ONE OF THE FUEL TANKS, RESULTING IN AN OVERFLOW OF FUEL PAST THEFILLER CAP.
Consequence Summary:
THE OVERFLOW OF FUEL PAST THE FILLER CAP CAUSES A FUELLEAKAGE, WHICH CAN RESULT IN A FIRE WHEN EXPOSED TO A SOURCE OF IGNITION.

 

That recall was not from the Ford Motor Co,
That was a NHTSA Campaign trying to get Ford to do something about that but I have never seen a recall from Ford on frame mounted "selector valve".

There was never anything wrong with the valve. The problem was that the driver failed to change tanks and keep using the same tank or would let the truck set for long stretches of time. This would cause the "O" rings to stick on there shafts and when the driver finely selected the other tank the return fuel would go to the wrong tank.

 

96F150XLT 1FTEX15N3TKA54509 DUAL TANKS, INTERMITTANT STALL, IDLE AND LOW SPEED, AFTER STALL WON'T START.TURNS OVER FAST LIKE IT WANTS TO START, BUT WON'T. AFTER A COUPLE MINUTES TURN OVER, LET OFF & QUICKLY HIT STARTER AND IT CRANKS. CODE READER SAID CRANK POSITION SENSOR WAS BAD, BUT IT DID NOT CORRECT. FUEL PUMPS ON BOTH TANKS CAN BE HEARD WHEN SWITCHED SEPERATELY. HAVE NOT CHECKED PRESSURE ON FUEL RAIL YET, BUT VERY LITTLE VOLUME OR PRESSURE WHEN FIRST TURN ENGINE OFF. GOOD VOLUME WHEN ENGINE RUNNING. SEPERATE INDICATION FOR SEVERAL MONTHS BEFORE STALLS STARTED IS REAR FUEL TANK EMPTIES KEEPING FRONT TANK FULL WHETHER REAR TANK IS SWITCHED ON OR OFF.
WONDERING IF A PRESSURE RELIEF VALVE IS BAD SOMEWHERE.
THANKS IN ADVANCE

 

Sounds like the fuel module is bad in the front tank.
Did you say you you replaced the PIP sensor in the distributor?
If not it sounds like that may be bad also.

 

Here is the link to recall:
1989 Ford F-250 Recalls & Problems - Motor Trend Magazine

 

No where dose that link say the recall was from FORD.
The only one I have seen from Ford was the 1993 one that said to replace the fuel pressure regulator as they were bad and letting the fuel pressure go to high and blowing out the high pressure check valve in the non selected tank. They also installed check valves on the high pressure lines leaving the fuel tanks to keep from replacing the FDM ($$$).

A lot of the dealers did install the check valves on the pre 1990 trucks to make customers happy but they just caused problems and had to be removed later on.

If you can fined a recall other than the on for the 1993 trucks from the Ford Motor Co. I would like to see it.
You are not the first one to bring this suggested recall up.

 

Recall ID # 20737 - FUEL SYSTEM, GASOLINE:STORAGE:AUXILLARY TANK:SELECTOR DEVICES
Recall Date:
SEP 04, 1991
Model Affected:
1989 Ford F-250
Summary:
THE DUAL FUEL TANK SELECTOR VALVE MAY MALFUNCTION AND CAUSE AN OVERFILL CONDITION IN ONE OF THE FUEL TANKS, RESULTING IN AN OVERFLOW OF FUEL PAST THE FILLER CAP.
Consequences:
THE OVERFLOW OF FUEL PAST THE FILLER CAP CAUSES A FUELLEAKAGE, WHICH CAN RESULT IN A FIRE WHEN EXPOSED TO A SOURCE OF IGNITION.
Remedy:
REPLACE THE DUAL FUEL TANK SELECTOR VALVE.
Potential Units Affected:
350000
Notes:
FORD MOTOR COMPANY


Read more: 1989 Ford F-250 Recalls & Problems - Motor Trend Magazine

 

This does not apply to his 1988 truck, this was for the all the 1989 F-series truck built after 3-1-89 and the 1989-1991 E-series vans only built after 3-1-89.

They are talking about recall #91S39.

 

Sorry to bring a thread back up but would a bad fuel tank selector valve cause a truck not to get enough fuel to start?

I have a 88 F250 351 that is not getting fuel. Tried starting the truck after it sat for a couple of weeks and it wouldn't start up. I've changed the front fuel pump which I know was bad but didn't fix the issue. The Selector valve is bad because it kept pumping gas into the front tank when running on the rear.

 

After reading all 17 pages I have learned alot, but I have a couple of question. I have a 1988 F250 7.3L Diesel with two tanks and need to replace the selector valve. First question is it the same for an 86 or is it a different part number (and what is the part number for the 1988)? Second question, I have checked the lift pump and the injector pump, are there pumps in the tanks themselves also? Thanks

 

Yes it can. But make sure both the frame pump and the selected tank pump is running. If it is pumping into the front tank then you have a stuck "O" ring on the return valve in the selector valve.
The frame pump can run the engine OK most of the time without the tank pump running but if you run out of fuel or change out the frame pump you need the tank pump to get the fuel back to the frame pump again before it will work. The selector valve may also be full of junk blocking the flow.

 

Your selector valve is much different than the one we were talking about above.
Yours has an electric motor in it to select the tank for the fuel flow and the gauge reading. When you change the switch on the dash the motor in the valve will run and change to the other tank.
IIRC you do not have a pump in the tanks only the one on the engine. In other words you do not have any electric pumps on the truck at all. I think some of the newer trucks did but I do not think an 88 did.

Below is the wiring for a 1992 but a 1988 is wired the same but the wire colors and numbers may differ:


/