I have a 93 F-150 6 cylinder that acts as if it only gets gas occasionally. It's got duel tanks and like another thread on this forum the front tank seems to be more reliable. Beyond that it also starts/runs better when the truck is parked going downhill. If parked going uphill it starts but acts as if it can't get any gas.
Recently while driving the truck would rev up all on it's own. It's actually rather dangerous considering I let off the gas to coast to a stop sign and right before I hit the brake the truck gives itself quite a bit of gas and I have to stomp the brake. Then I look like a total jerk cause the truck is setting their reving itself the whole time. Or it dies.

The problem has evolved overtime. Use to be it would only have this problem on hot days when I drove it alot. Then it started having this problem worse when it got below a quarter of a tank. Thinking about the problem for a while we've come up with alot of possible problems and I'd like your input on them.

1. Clogged filter inside the tank.
2. Bad fuel pump
3. Clogged fuel filter

My stepdad thought it could be the filter inside the tank considering how much better it runs with a full tank. Like the pressure pushing down allows it to pass. The bad fuel pump idea came from when I took it to get repaired. I took it twice to a guy my grandpa recommended. $270 one time $230 another time. Neither fixed it. It's been a while I forget what he SAID he did. Stepdad recommended a friend of his he gave it a tune up and replaced wires he said were long overdue, that cost me $200 and something. Seemed to run great for a while but problem resurfaced. The guy I essentially gave $500 did mention the rear fuel pump was about to go out. He said it would be like $350 for the part or something like that. My Uncle said he got a used one for $75 which sounds alot better to me.

I'm truly hoping for #3. I bought a new one but have never done it and no one I've talked to has either. One guy mentioned a special tool to unlock some sort of plastic holder.

My automotive knowledge is around the general maintainence. Replacing brake pads, or even brake hoses, that kind of stuff. Nothing to do with the fuel line. Not to mention I don't have a garage and all the tools. I have a sidewalk and a good number of tools.

So any input in general as to the cause would be great. Any heads up on replacing the fuel filter would also be great. And mentioned somewhere else on this site and by a guy I know who explained at the local Ford dealership when they are replacing a fuel pump they remove the bed of the truck to make it easier. That is a common practice then?

Well thanks for your time, hope to get this fixed this time.

 

Replacing #3 is a good idea to start off with, even if its not the case, its an easy to do, inexpensive item.

#1 and #2 can be confirmed by hooking up a pressure gauge to he fuel rail, and trying to start the truck. The gauge should read in the 45psi range, give or take 2-3 psi. With the truck running, it should be in the same range, even if you rev it a bit, the pressure should remain in the 40's.

If not, the problem is either the fuel pressure regulator at the end of the fuel rail, or the fuel pump, or the filter in the tank. Again, replacing the regulator is the cheapest, easiest thing to do. If that doesn't work, then I'd drop the tank and replace the filter and the pump (do both since dropping the tank is a pain, and you don't want to have to do this again in a few months).

If you do have the proper fuel pressure, your problem might be elsewhere. With an EFI truck you could have a bad MAP sensor, a bad o2 sensor (which causes the truck to run rich, or lean), so you might want to check sensors as well.