Finally burnin WMO - couple new ideas

[fsr7]

Hey all -
Finally filtered some of the wmo I have around the shop and dumped it in the rear tank - I'm psyched. I don't want the fuel in the front tank to get "contaminated", so I bypassed the return side of the tank selector valve so that the truck is always returning fuel into the rear tank, regardless of which tank the fuel is coming from. I needed a way to make sure the rear tank won't overfill when I'm starting/shutting down on the front tank - So I went the the trusty old Checker and got an on/off/on toggle switch. Hacked into the wiring harness at the selector valve - my '86 has a yellow/bluestripe wire coming from the front fuel guage sending unit, a blue/yellowstripe from the rear, and a solid yellow wire going to the gauge. I hooked these three wires up to the switch mounted to the right of the wiper knob. Now I can flip the new switch to change which tank the factory fuel gauge is reading, and the original tank selector switch still controls which tank the truck is running off of. Works great! Before I dumped WMO in the rear tank, I ran the truck for about 45 minutes on the front tank to see how much fuel will actually pass through the motor and back into the rear tank. It was more than I expected - in the 45 mins, It moved between a little more than 1/4 of the front tank into the rear. It'll certainly work for me for now - I only plan on using the front tank to shut down/ start up. The only catch is that if I have running problems on the rear tank when it is near full and I have to get somewhere on the front tank, I will have to crawl under it and swap my return line... but who has running problems I'll hope for the best.

 

[subway]

you should be fine, you might have to replace the filter more often but for the money saved its worth it. what mixture you running? anything over 50/50 shouldent cause you any problems on a stock system.

 

[fsr7]

I've got a spare filter in the back and some diesel kleen to fill it with... 70/30, maybe? I put lots of oil in it and a couple of gallons of diesel when I fill the front tank... and whenever I'm running on the front tank, it fills the rear up with some clean stuff. No problems this weekend - I made an offer on an '83 6.9 I found with a transfer tank so I can set up an on board system like what (towcat, maybe?) is putting together. Hopefully that deal comes through.

 

[discbrks]

I ran the truck for about 45 minutes on the front tank to see how much fuel will actually pass through the motor and back into the rear tank. It was more than I expected - in the 45 mins, It moved between a little more than 1/4 of the front tank into the rear.

I thought the 2 fuel tanks were completely independent of each other - meaning, if you run on the front tank, then your return is also on the front; and if you run on the rear tank then the return is on the rear. Isn't that why the selector valve has 6 ports? Or am I missing something here?

 

[fsr7]

I don't want the fuel in the front tank to get "contaminated", so I bypassed the return side of the tank selector valve so that the truck is always returning fuel into the rear tank, regardless of which tank the fuel is coming from.

You're right - in a stock system, as soon as you flip the switch, it starts getting fuel and returning fuel to whatever tank you just switched too. I basically just ran a direct line so its always returning to the rear.