fuel pump - Diesel Forum

wwileyii · 01-02-2006, 08:31 PM

Hello to all. I'm a newbie with my first diesel an 88 F250 4x2 7.3L. 174000 miles. I read most of all of your posts on how to correct things and you have been a big help. I have one problem that maybe you can help me with. My front fuel tank holds 29 gals and rear holds 19. When I'm feeding from the front or the rear tanks I use appox 12 gallons of fuel out of each and the truck starts to die out when I come to a stop. I get maybe 240-250 miles out of this truck. I've checked everything that I could think of and I'm at a lost. I changed all the filters and had IP rebuilt all with new GP. Hopefully someone could help me solve this problem. Thank you.

OkieGringo · 01-02-2006, 08:50 PM

Hi, unless the front tank has been greatly redone, there is no way it holds 29 gallons. If you have a reg cab, then it is only 17 gallons, rear 19 gallons. A Crew Cab front holds 19 gal, rear 19. The problem you're having is the plastic bottom end has broken off and the fuel pickup can't reach the last 1/4 tank.
It's time to drop the tanks and check/replace the sending unit/pickups. There is a plastic extension on the bottom of the pickup which contains a by-pass valve and the filter/screen. Unfortunately, this plastic part breaks off and/or the by-pass valve rots (rubber). It is there to allow the engine to get fuel if the bottom of the tank has enough water to freeze and plug up the normal pick-up.
If the plastic has broken off at the top where it attaches to the metal tube of the pickup (as both of mine were) you'll run out of fuel at about the 1/4 tank level. The new sending unit/pickup is a "Ford Stealership Only" item. Go here: http://www.parts.com/partlocator/ind...?siteid=213787 after selecting your make and model, you need to look under "Electrical" to find the fuel sending unit. The 'units' are about $20.00 less at this site than at a "Stealership"($100.00+/-), but I don't know if "the shipping charges" will make it less in the long run. The front and rear units are different with different part #s. And even NEW sending units aren't very accurate. When/if you install new SUs fill the dry tank with 5 gallons of fuel and check what the gauge shows, add 5 more, check etc...
Rather than replacing the whole sending unit, some people have just added a diesel rated rubber hose with some kind of screen to end of hose. I'd tee it at the bottom of tank then reach to front and back. The original plastic screen does not have a fine screen, it's too hard to suck thickening cold diesel fuel thru a fine screen. There is a screen bypass valve on the upper part of the OEM plastic unit. If the bypass valve gets crap stuck in it or if it rotts away it will allow fuel in the line to run back into the tank..loosing the prime...allowing air into the system [img]/ubbthreads/images/graemlins/eek.gif[/img]. [img]/ubbthreads/images/graemlins/smokin.gif[/img]OkieGringo

Gibson · 01-02-2006, 10:45 PM

bah! you don't need no stealership junk! just do what I did.

get the fuel tank on a bench or tailgate and get the seding unit out and then dump everything out of the tank (try to save the fuel first) then clean off the the longer tube on the sending unit and take a piece of 3/8"ID fuel line and stick a T fitting on the end that will sit on the bottom of tank and re-install in the reverse order. it was worked over 3000miles so far..............Gibson

OkieGringo · 01-02-2006, 11:01 PM

[ QUOTE ]
bah! you don't need no stealership junk! just do what I did.

get the fuel tank on a bench or tailgate and get the seding unit out and then dump everything out of the tank (try to save the fuel first) then clean off the the longer tube on the sending unit and take a piece of 3/8"ID fuel line and stick a T fitting on the end that will sit on the bottom of tank and re-install in the reverse order. it was worked over 3000miles so far..............Gibson

[/ QUOTE ]

If you live in a warm climate like Gibson here, sure you can get away with just using rubber hoseand a tee. But if you live in a climate where Gelling is caused by COLD TEMPs, I'd recommend getting new units. There is a rubber valve at about 1/8th tank that allows fuel to be drawn in if the bottom screen gets gelled up and antigell hasn't de-gelled all the fuel. It's up to you, obliviuosly [img]/ubbthreads/images/graemlins/biggrin.gif[/img](yes, I know....it was a joke, obviously [img]/ubbthreads/images/graemlins/rolleyes.gif[/img]). [img]/ubbthreads/images/graemlins/smokin.gif[/img]OkieGringo