I own a 1989 F350 diesel equipped with duel tanks.

Today I noticed fuel running out of my "front" fuel tank inlet (where your fill your tank). I looked a my fuel gauge indication showing empty on the front tank. I selected my fuel switch to the rear tank and it too would show empty. So now both indication of the tanks showed empty where they never did this before.
I just filled up my front tank however, I did not top it off.
At first I figured my problem was needing a new fuel cap for the tank due to a bad gasket seal. So went to NAPA and purchased a new fuel cap for the truck's tank and installed it. Still fuel would pour out of the tank while driving down the road

After driving down the road I could see fuel pouring out of the cover of the cap fill. I pulled to the side of the road and gently cracked the fuel cap open and fuel just poured out of tank fill. I crawled under the truck to check the fuel tank vent line and had a plastic plug on the fuel line with a few drops of fuel coming out of the line.

Seems there is some serous fuel return pressure coming back to the fuel tank and over filling it for some reason....

Could this be a faulty fuel selector solenoid valve? Or is this the result of something more serious?????

HELP!

 

It sounds like you have a plugged line somewhere in the return or a bad selector switch.

There was a recall that addressed this, but it wouldn't apply if your truck just started doing this. Based on all the red type and underlining, I'm guessing this is a new behavior.

 

sounds like a bad selector valve, this is not the first time i have heard of something like this, it pumps fuel into one tank and returns it into one tank, the one tank it puts it in however is not the one it got the fuel from, there fore overflowing the tank it its putting it in, all because of the selctor vave being stuck,

 

Yes ... it just started this .. however, being over 10 years old .. anything is likely to happen. I failed to mention I checked my fuse (electrical) for the tank switch (dash board)/solenoid valve (fuel tank selector - under truck). The fuse was good.

I was wondering if it my be my solenoid valve??? either solenoid died or something internal of the valving is not switching over. Not to mention the loss of my fuel indication - signal being selected between tanks.
I did notice the wiring going to the solenoid valve (fuel tank selector) having several wires plugged into it.
Because of the wiring harness is so wrapped up with tape and protective covering, I could not identify any of the wires or where they go.

Priced a replacement today which would cost $72.00 (non motor) and $76.00 (motor type). WHICH brings me to another question????
Is the motor type referring to a tank mounted electric fuel pump?
Having a diesel, my engine has a mechanical mounted to it verses electric driven.
Asked the parts store guy and he didn't know the difference in the two, other than one was motor type and one was not.

Thanks guys for the reply ... Getting ready to make a very long haul from NY to Texas then to Nevada .. Would really like to get this thing straighten out with out the high prices from the FORD house...

Sure will loose a lot of fuel along the way .. LOL! .. would like the engine to use it verses leaving a trail from NY to TX ... LOL!

 

i want to say its a motor driven, because of the fact that the place i work at has an 89 f-350 7.3l and you can hear it select, while my f-150 is silent in its operation, the f-350 we have has a defident motor sound. there must be a way to look at it and tell though