I have a 1985, F150 with dual tanks, fuel injected, and a 302 engine. Its been running great until a couple weeks ago as I could tell it wasnt getting enough fuel. Two days ago I was driving it, and it started sputtering really bad. Then a few seconds later, it completely died. It tried starting right after that, but evertime I pushed the gas, it would die, so I had to get towed home. Now it wont start at all!! From what I have gathered, its the fuel filter, but there is no inline filter? Ive followed the lines everywhere. Ive read that there is a filter in the fuel reservoir but some people say do not take it apart, and others say do take it apart. I just need some input on what to do. Its my only vehicle and Im stranded now, and I am no mechanic what so ever. Any help is highly appriciated. I need to know where the filter is, or what else can be causing this. Some say theres an inline filter right in front of the high pressure pump, but its not on mine. Im confused. Please help!! Thanx in advance

 

there is a filter in that line just after the selector switch which can be confused with a high pressure fuel pump try looking under the driver door just inside the frame rail or in front of midship tank it could be hidden in a clip that holds the filter in place

 

Ok, I'll get heat for this, but this is a 'one year' truck that Ford built with that (very) specific type of fuel system. What I mean by this is, is that just about everything on this powertrain was revised the next year. For example (if my memory serves correctly), the airbox on this truck was on top of the engine, not off to the side like every year after.
If you've isolated the problem to the fuel system (and I think you're right), then this is what's probably happened; the in tank (low pressure, maybe 10 psi) is running, and the rail pump (the one that boosted the fuel up to about 40 or so psi) quit. Which is why it ran and died when given gas.
These did have an inline fuel filter, which was usually mounted to the frame fuel pump housing. But there's more.
There was another in line filter that was used for this one year that resided just forward of the front tank. There was a circular housing to it, that had another filter (and 0-ring seal) that most people didn't know about.
It's very likely that that filter has never been replaced, which starved the rail pump and probably took the lift pump (in the tank) with it. I replaced a lot of these, and whenever the rail pump ran dry (due to a plugged in-line filter), they went bad.
It's usually really tough to remove these filters; I've broken a bunch of them. You can try with an oil filter wrench, but beware. I've never been a fan of this system, and they did change it the next year.
One other thing: on anything this old, it's totally possible that other work has been done, and the system was modified from original.
Good luck!

 

Greasemark, just how hard is it to put in a high pressure pump in the tanks run the lines through the selector then through the filter and finally to the engine? Because I haven't
seen a throttle body on any Ford truck ever. it's always been fuel rails or multipoint fuel injection not central fuel injection like they did in the merc. grand marqueis

 

I've heard a few things about that year f150 from other sources as well. I have heard that there were some that only had the 1 filter in that reservoir and some had more than that. Ill look in the morning for an inline filter since its dark right now. I've looked about 20 times already, and cant find one for the life of me! As for the High pressure pump that i think your talking about, it didn't quit. I hear it go on when I turn the key. I'm hoping its just an easy fix it like getting a new filter. As the truck being modified, I'm seriously doubting it. It was owned by a really old man that passed away recently so his wife sold it to me. He had it since it was new. Its in really good shape, exterior, interior, and only has less than 80K miles on it. That's why I'm hoping this is just a minor problem. I never fill the tanks cause its too much $$$$ since I'm in Cali. Maybe only putting 10 bucks in each tank every time I get gas isn't too well for it either. 1 more thing, It started doing this when the temperature here started getting over 100 degrees, the truck doesn't run hot, but always acted up in the heat, but ran fine at night time, and finally just quit.......

 

I wonder if that thing ain't vapor locking on you. I built a t-bird one year and it would run like a stipped assed ape till it got good and warm then it would up and quit like it was running out of gas until the next day or it cooled off enough to keep the gas flowing to the carb. the best thing I figure the fuel line ran way too close the manifold

 

I thought it was vapor locking too, but its been 2 days now and still wont start. So that cant be it either :-(

 

This is ford EFI, it's just the very first interpretation of it. Electronically, it works the same as the later EFI; the implementation of it is a little different.
This should have a lift (low pressure) pump in the tank, and the high pressure pump, which was usually located just about under where the e-brake is under the truck on the frame. It could be moved a little from one posisiton, but it should be there.
Like I said, it is completely possibly someone reworked this system, and I've seen these where high pressure pumps were put into the tanks and the rail pump was removed; just food for thought.
You might wish to double check power to the pump; the Pink/black wires will have power for 2 seconds when the key in turned on, then go out until cranked.

 

Ok, I replaced the filter and the truck is running great now!! But now I have another problem. My fuel tank selector valve is leaking pretty bad when the truck is running. I went to a few autopart stores and they have them, but the wire hookup is different because they're universal. I cant find the original that is on my truck. Is it a pain to re-wire it so it works on my truck? And I need a 6 port valve, they sell the 3 port valve for $30 cheaper that looks exactly the same, but they have three of the ports capped off with rubber caps. Can I pull those caps off and use it as a 6 port to save 30 bucks? Or is it built different on the inside? Thanx for everyone's help. By the way, heres the old filter I pulled out, pretty nasty!

 

glad to hear that you got it going, and yes, Mr. Grindman, it WAS vapor locking, because the pressure wasn't what it should have been.
As for the selector valve, you might try Vintage Ford; but these selector valves were getting scarce a few years ago, so it might be hard to find an original.
You might just be stuck having to modify whatever you can get; it's not the first choice, but sometimes you have to do it.