I have a 2001 f150 4x4 5.4 extended cab 111000 miles

2 weekends ago my truck took about 20 seconds of cranking to start. When it started it ran fine and started once again about 10 minutes later. After a 10 mile drive the truck wouldnt start again. After about 45 minutes some guy came by just as I was adding some fuel (the fuel light was on) and tapping the fuel filter. He said to press the pressure release on the fuel line under the hood. It fired right up after that.

Either it fixed itself on its own, the extra fuel helped somehow, or tapping the filter caused it to be able to start again. The fuel pressure was really low and after pressing the valve my buddy under the truck said he heard the fuel pump come one again. I replaced the filter the next day and a bunch of brown fuel came out of the gas tank side of the filter. After that I filled the tank all the way up with fuel.

It has ran fine from then , 2 weeks ago, until yesterday it wouldnt start again. The gas light had just come on a few miles earlier. After about 30 minutes I tapped the 2 week old fuel filter and added 5 gallons of gas and it started right up. Drove right to the parts store and bought another fuel filter. Changed it out and it started and ran fine. The fuel in the filter was perfectly clean this time.

I drive this truck on average about 75 miles a week. I usually have it below a quarter tank of fuel. It has stared hard or failed to start within 1/2 hr or more int the last 2 weeks. Where should I begin to look for the problem. Thanks

 

Stop doing that! You are cooking your fuel pump. You may want to drain all the crap out of your tank and start fresh.

 

You should maintain at least 1/4 tank of fuel, the pump needs the fuel around it to work as a coolant.

However getting wifie to keep fuel in the Expy is a loosing battle. On that truck the low fuel light means you have about 3 more inches to go before it runs out. It's more like a "Hey you just ran outta gas STUPID!" light, my 150 will go about 25 miles.

Point is don't run it low, and tapping the filter doesn't to squat unless it is old and clogged. Even then it's marginal.

 

The first fuel filter was old and dirty... nasty dirty. Also, 90% of the time I have a quarter tank or less, for the last year and a half. I only drive it on the weekends to the store and back. Did I kill my fuel pump? If I have to clean out the tank should i spray somthing inside of it? Ive never had it out but I imagine there will be a large hole in the top where the pump and sending unit go in that I could clean it out from right?

 

Your at the point where the original fuel pump can just go out. You may have a small leak internally. Since you have a new filter installed, it's a good time to test pressure and the regulator to determine health. Watch the bleed down as well. Also, make sure your not over pressurizing the rail. Write the numbers down after fuel system diagnostics. We can more helpful after doing so.

 

WHY? What's so hard about filling it up and refueling it before it gets so low? If you are one of these guys that puts in 10 bucks at a time every time the light comes on, FILL THE DAMN THING UP and put in 10 bucks every time it gets down to 3/4! There's no difference in cost here except for the one-time fillup.

 

Can you give me a few more details? Im not farmiliar with the procedure. I need to get the gauge that goes on the schraeder valve on the fuel line, right? Do I run the engine, or just turn the key to run and let the pump build pressure?

 

Both, record the static pressure,running pressure and the bleed down pressure after you turn off the key (see how long it holds and what it goes down to).

 

Thanks, Ill see if I can get a gauge tommorow.

 

Auto Zone has that free loner program. You have to leave a deposit for collateral, but you get it all back. Unless you just want to purchase a cheap gauge. Just make sure whatever you use, that it has a FORD adapter.

Also, yea, - that petrol in the tank might be going stagnant on yuh. You may want to drain her out and use it to varnish your work bench.
Each of your injectors have a cupped filter screen @ their inlet. They really don't clog all that much and I'm not saying this is your problem, - it could be or it could be adding to. Like glc stated, -keep more fuel in it and I'd even run a stabilizer. The stabilizer will stay on top, capping petrol in the tank, preserving those good impurities that keep all 8 running happy, -allot longer anyway, if you know what I mean..

 

Autozone's kit says 35-55 psi operating range. Over the course of 24 hrs it dropped to nothing, Im not sure if it is supposed to maintain some pressure for days at a time. Mine has 30 with the key on which drops to about 27 in the first minute, after 10 minutes its more like 21 psi. When I start it the pressure bounces around at about 32 psi at idle and doesnt change from there.

I think my pump is either going out naturally or I burnt it up because I never keep gas in it. Both times it stranded me it didnt have enough fuel in the tank (gas light on) to cool the pump and the hot pump couldnt supply enough pressure to start the engine once it was shut off until the pump cooled. Both times splashing 5 gals of gas in the tank fixed the problem, possibly by cooling the pump down enough to operate. Am I on the right track here?

 

You almost got it. The low fuel causes the pump to run hot, it's a little electric motor. The heat causes the motor and pump to wear prematurely, it's shot.
Adding the fuel worked b/c you were out of gas. Once the fuel level reaches a certian point it won't suck up any more, like the end of a milk shake.

Fuel pumps are funny critters, some just up and drop dead while others slowly go kicking and screaming-yours was the second kind. It died an early death b/c it wasn't properly cooled-that's why you want to keep a minimum of 1/4 tank in there. Alot of the junk that came out of the filter was worn off of the fuel pump. Get it?

 

Its funny, I never ran out of gas, it just failed to start wherever i shut it of at because of a low amount of gas. Ill get a pump today. Thanks