Hello all,

I recently got a 1986 F250 6.9. It's missing the fuel selector valve and is currently running off of the front tank only. I think it's missing the fuel/water separator too (can this be moved? I don't see it on the firewall per the diagrams).

There is an inline electric pump installed inside the frame rail near where the selector valve should be. The rear tank has a pinhole in it, and there's air in the clear line coming off of the fuel filter (is this the return line?).

Also, when I hit the Schrader valve on the fuel filter, no diesel comes out. There seems to be a heat soak issue as well...it lights right up when hot or cold but in between and it'll just turn without a WTS light coming on.

The WTS light also stays on for 2-3 minutes after the truck starts. I think my controller may be going and I'm planning on installing a manual GP switch.

Lastly, there's a black wire to the inline fuel heater right before the fuel filter that is disconnected...where is it supposed to go?

I've found most of the documents/tutorials to fix these issues but I'm trying to figure out what all I should do immediately to make starting more reliable. I'm in the process of buying a house so money is tight.

Do you think the missing fuel selector valve could be the source of my air intrusion? I'm trying to figure out all of the lines but I'm wondering if the rear tank return line was ever plugged or removed or what? If it's just open to atmosphere, that could cause intrusion right?

Could I install just the selector valve and lines and replace the rear tank later?

Also, do I need to add SCAs with the 6.9? I've gotten a lot of conflicting advice on the FB page.

Any help, ideas, tips, and links to cheap parts are greatly appreciated. This is my first diesel so please excuse me if I'm getting anything wrong.

Thanks!

Am I missing the fuel/water separator?

Inline pump only going to front tank. Disconnected blue line...return for back tank?

Is this bend an issue?

Loose wire on inline heater.

Missing the selector valve.

 

IF I was you I would leave that Line Heater disconnected ... it's probably shorted anyway and will cause you problems if you re-connect it.

on the return lines inside the Tank there is rubber check valves when they fail it causes bleed back from the filter to the tank especially IF you only have the Orifice in the filter head and not a check valve.

the Valve in the tank on the return lines is called a Duck Bill Check valve.

 

I think, SCAs are less critical on the 6.9 than the 7.3.

I guess, if it was me, it would depend on my intentions for the motor. If I intended to run her a good long time...I'd go the SCA route.