Super Duty fuel pump / selector valve troubleshooting

[cbuttre835]

Ok. Im running a "baby fuel" system; a Super Duty pump after the factory selector valve, feeding into a spin-on filter. The truck died the other day. I had swapped tanks, the gauge moved, but it died at enough miles for the tank I was on to be empty. Checked the fuel pressure gauge under the hood, it was stuck. Got home and when I removed the gauge to put on a new one, the system had trapped air.

Fuel pump is only delivering air. It is running.

Selector valve does nothing, and now the gauge wont move either. #6 fuse (it, and tge a/c comp clutch) is good. Also, when I swapped tanks initially, the level went wayyyyy past full. Kind of weird.

Questions:

If I have good flow thru the selector valve, should I be able to start a siphon or use a suction pump to get fuel out and onto the ground (lower point for siphoning)?

If this SD pump is good, should I be able to put the pickup tube into a bucket of fuel and it pump some? Or does it need to be "primed"?

If I ditch the selector valve - Can the stock OBS tanks be sumped easily, like with a Bean's Diesel Sump?

Can a plastic 38 gallon Bronco tank be sumped? (asking these 2 questions because the sump needs about 4"x4" Ive read.)

 

[ghohouston]

My selector valve failed between positions. Had the same setup. Got rid of it, and installed a sd 38 gallon plastic tank with hutch and harpoon mods. No problems since.

 

[cbuttre835]

My selector valve failed between positions. Had the same setup. Got rid of it, and installed a sd 38 gallon plastic tank with hutch and harpoon mods. No problems since.

Which 38 gallon tank? I'll have to re read the mods you listed, I've heard of them before but can't recall them.


There was a guy on Ford-diesel.com who sumped both factory tanks, and left them tied w/o a selector to self balance their fuel. He could get 40 gallons out of the 17 and 19 factory tanks. I'd like to try that with a big rear tank, if I could keep the tops and bottoms relatively level.

 

[Magnum PD]

The broncos had a 38 gallon tank

 

[5 oh]

The tank in my obs is sumped. I have the selector valve you can have for free. PM me for details

 

[lincolnlocker]

Could be a ground issue also.

SD pumps are self priming.

live life full throttle

 

[ghohouston]

Which 38 gallon tank? I'll have to re read the mods you listed, I've heard of them before but can't recall them.


There was a guy on Ford-diesel.com who sumped both factory tanks, and left them tied w/o a selector to self balance their fuel. He could get 40 gallons out of the 17 and 19 factory tanks. I'd like to try that with a big rear tank, if I could keep the tops and bottoms relatively level.

A super duty 38 gallon plastic tank mounts where your current front tank mounts. Never have to worry about rust, or a selector valve. I think i paid close to $400 from Ford 2 years ago for a new one. And that was at cost. Why even have the worry of a 2nd tank?

 

[cbuttre835]

A super duty 38 gallon plastic tank mounts where your current front tank mounts. Never have to worry about rust, or a selector valve. I think i paid close to $400 from Ford 2 years ago for a new one. And that was at cost. Why even have the worry of a 2nd tank?

Cool. I've only looked for the 33 or 38 gallon bronco tanks. I'll dig into that for sure.

 

[wildbill963258]

Could run a 38 gallon sd tank and a 38 gallon bronco tank in the back and just have the rear tank fed into the front tank

 

[old man dave]

Rockauto lists the 38 gallon rear tank as a tank for a 1988 F-250 351. Spectra Premium F26E. About $133 at Rockauto. More or less a bolt-in.

The 33 gallon tank is the Bronco one.

 

[cbuttre835]

Rockauto lists the 38 gallon rear tank as a tank for a 1988 F-250 351. Spectra Premium F26E. About $133 at Rockauto. More or less a bolt-in.

The 33 gallon tank is the Bronco one.

Cool. I had read elsewhere that the 88 *Bronco* 351 was the 38 gal., but I could only find the 33.

I wonder if the 38 has a flat enough place for a sump...???

 

[cbuttre835]

Thanks to 5_oh; tested a known good selector valve by applying + / - 12VDC to pins D and E on the selector - it swaps and holds position once DC is removed. The one on my truck is definitely not working - this valve makes a very distinct sound when operating.

Gonna disassemble the bad one - it's held together with clips and rivets - will advise on what the innards look like.

 

[m j]

do not waste your time with bronco tanks. buy the 38gal tank from spectra that bolts in f26e / f26d .

 

[cbuttre835]

It's on the way... be here tomorrow.

d selector valve motor burned up. Bad enough that the insulating varnish cooked out of the little rotor and locked it up.

It's wound with AWG #37 wire. Not gonna try to fix it...