I have a (1996 F150 EFI 4.9L IL6 4X4 E4OD ABS) that I'm starting to take on as a project and a couple days ago the engine would not start, it cranked fine but no fuel. I switched to the rear tank it fired right up, I then switched back to the front tank and it ran fine for a few minutes then died so I figured the fuel pump on the front tank had died. I thought no problem, I'll just operate from the rear tank for a while until I get enough money ($200) for a new pump and some warmer weather then swap out the pump. Well after filling the rear tank and going for an extended drive I noticed the gas gauge seemed to be dropping extremely fast. I ended up spending over $100 on gas for a trip that normally only took about $50, so I did some reading here and read about the common problem of the rear tank siphoning to the front tank when the front fuel pump dies, I went out and turned the switch to the front tank and sure enough its almost full and it was almost empty when the pump died a couple days ago.

So I'm reading the Haynes Repair Manual book I have for this truck that says its for Ford Bronco's and Pick-Ups 19080-1996 2wd and 4wd and I still cant tell exactly what fuel tank switching system was used on this year/model of truck. I'm trying to diagnose this whole fuel switching and pump problem to see what I might be getting into before I start. Does the fact that rear tank is siphoning to the front tank mean I will have to replace something else besides just the pump like a check valve or something? This haynes book has me mystified and it seems that %99 of the book never applies to this specific year of F150.

One thing I really need to know about this rear-to-front siphoning problem is "What happens when the front tank gets completely full? Does it end up going out on the ground?"

I might as well throw in another item while I'm here, this truck was hit in the driver side and crumpled the cab and the bed in and smashed the front leaf spring hangar back about an inch or two. The rear leaf spring hangar/shackle was totally broken and someone fashioned a homemade hangar/shackle from plate steel and then welded it to the frame of the truck but about and inch or two too far back which moves the rear axle way out of alignment and makes the truck dog-track pretty bad. If I'm going to be serious about putting some effort into this truck this part will definitely have to be fixed but is something I've never worked on (I'm usually just a oil change/spark plugs/brakes/water pump/etc kinda guy). How hard will this be and most importantly is this even a possible fix? I looked at that rear homemade hangar/shackle thing and it just has a thin vertical weld along both ends to the frame and could probably be ground off with a grinder. The original hangar mounting holes appear to still be there although maybe slightly deformed. I found Autozone carries the hangars and shackles for this truck for not a bad price compared to the price I got from the local Ford dealer in town.

My main question regarding the (leaf spring/rear axle) fix is how do I measure the frame and axle for squareness when putting it all back together? Also, there happens to be a broken leaf spring (first one down from the main top spring on the passenger side) that is missing so I will have to replace it at the same time and I would like to "add a spring" to each side to increase the carrying capacity if possible.

If I end up with enough money to tackle all this at once would it be worthwhile to just pull the bed off the truck and do the fuel pump and the springs/axle work at the same time?

If anyone has any helpful hints or suggestions I'm open to any ideas or criticisms because I really don't know what I'm doing.

Oh yea, the E4OD recently decided to stop downshifting all the way to first gear when I come to a stop while driving also. I have to shift it out of drive into second manually to get it going then shift into drive at about 25-30mph, other than that it shifts to and from OD fine.

The engine light is on usually, it goes off occasionally but always comes back on. The ABS light comes and goes also but is usually on. The "OFF" light on the gear shifter has always been flashing also.

If you need to know anything else just ask me, also I will get some pictures of the whole leaf spring deal tomorrow to get a better idea.

Thanks in advance,
topconsurveyor
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same damn thing is happening to me. i'm constantly having to switch from the rear to the front, then driving until that drains then back to the rear. subscribing to this thread

 

I can't wait for a reply any longer on the fuel tank situation, I had to take a long drive today and the front tank finally filled completely up the neck to the cap. If i take the cap off gas starts spraying out. At this time I had to take a long drive home and found the gas mileage to be back to what it used to be so I'm not siphoning any more gas out I was just worried it may start pumping out an overflow on to the ground or something.

I'm going to buy a new pump and sending unit for the front tank and warm up the garage and just do it. I wonder if it's possible to get a siphon hose down in the tank to empty it first on this year truck?

 

You need to get a complete fuel pump assy for the front tank. That will fix the transfer problem and the no start. First, you could try smacking the bottom of the front tank (with the fuel switch on the front) while someone tries to start it. This may jar the pump loose and make it run. If it does start, just drive it around to let the fuel burn out. It may run for a month, or a few minutes, just don't know. As long as you know the rear tank works, I wouldn't worry about it. You can get a hose down in the tank, however.

 

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Hey topconsurveyor, don't ya wish Ford would have just put a single damn 30-35 gallon tank on these things?? I too am in the middle of trying to figure out which tank of my dual tanks is back flowing with strangeranger and steve83s help. Good luck to you!!

 

I'm have the same problem with my 1995 ford when i switch tank mine drain back in the front tank but my front tank still runs but it acts like it is missing

 

have yall tried replacing the actual tank selector valve? both front and rear tank draw from go through the entire fuel system and the unused gets shot back into the tank. if your selector valve is malfunctioning it could be drawing from one and putting it in the other.

 

Not on a 95. There is no selector valve just a switch which tells which in-tank pump to operate. If his 95 is transferring fuel then the shuttle valve in the Fuel Delivery Module (Ford's term for the complete fuel pump assembly) of the tank which is receiving the excess flow is leaking and the FDM in that tank must be replaced