I have an 2001 F-150 with approximatly 192,000 mile on it. Everything works on the truck but about 2 weeks ago I was on my way home from work and the truck started to miss all of a sudden. I was on the bottom 1/8 of my tank. Just about time for the low fuel light to come on. I had to pump the foot feet to keep the engine going. It died on me a couple of times and I had to restart it. I got to a gas station and put about 4 gallons of gas in it and the truck drove home fine. Thought it was my fuel pump so I put a brand new fuel pump assembly into the tank. The stand, float, pump, and everything else. Next tank it did it again. The fuel filter was replaced about 6 months ago. It did not do it on the tank after that but it did it on the following tank of gas. It runs fine outside of the last 4 gallons of gas in the tank. I do not know were to look next. I have been getting gas at the same gas stations that I always have been. I do not know what is causing this issue. Help Please.

 

Did you dump all the crap out of the bottom of the tank when you changed the fuel pump?

 

Did you drain the tank? You might have 4 gallons of water in the bottom of the tank. Good luck.

 

No I did not dump out the tank. I just lowered it to replace the whole pump assembly. The first two tanks that it messed up on were on hot days. The next tank that it did not had an ambient air temp of 88 degrees and I was able to go down into the low fuel light with out a problem. The following tank started acting up on a 94 degree temperature day before the low fuel light came on. If I had debris in the tank that should not allow for the one tank anomaly should it? If I had water in the tank than it would do it all the time because water is denser than gas and would sink to the bottom of the tank where my pump inlet is located or am I wrong on these statements?

 

You are correct water is heavier that fuel. I do not know about technical issues that would create your situation. I just first thought of the obvious. My thinking is the water/debris level may be very close to the level of the fuel pickup point. Fluid sloshing around could cause the erratic symptoms. Seems cleaning the tank is something you can do to eliminate that as a possibility. Hope you can find the problem. Hopefully someone with more experience than i can chime in here. Good luck.

 

Stop running it down to the low fuel light. The pump needs to be immersed in fuel to keep it cool. Unless it's an emergency, get gas when it gets down to 1/4.

Dump the tank and change the filter again.

 

The problem is very inconsistent. It only occurs when the temp is up close to 100 degrees. It started to act up around 1/2 tank of gas now. It only occurs on extremely hot days. I use up almost all the fuel in the tank and the truck will run fine on days where the ambient air temp according to the truck is below 94 or 95 degrees. I have replaced the fuel filter back at the start of the year. I have a new fuel pump, Throttle body position sensor, and idle air control sensor. When the problem occurred on the time before last I replaced the throttle body position sensor and the truck seemed to run fine right after I did that. When it occurred this time I pulled right into a gas station and I had aver 3/8 of a tank of gas. I then added 4.8 gallons and started the truck and it ran perfectly fine. I replaced the idle air control sensor because I was having problems in Winter with the truck wanting to idle when it was first started on days when the air temp was in the single digits. I don't know if this was a separate issue or not. I have not verified that because it warmed up. Still not throwing a check engine light. Any help as to what to look at would be great. Seems to be a temp related problem.

 

Fuel pump driver mounted on the rear axle could be in question

 

1. Post is 5 years old.
2. 2001 doesn't have a FPDM.

 

What bradname pump did you buy? If it wasn't a Delphi you messed up.

 

Nothing wrong with a Motorcraft, Denso, or Bosch pump.........

 

​​​​ I've seen this before only thing I know thats worked is cleaning or replacing the mass air flow sensor. I know on my 97 4.6L XLT super cab whenever it feels sluggish or the weather's changed or sometimes I notice it's drinking a lot more fuel than normal the first thing I do is clean the throttle body and the mass air flow sensor and I took that damn air intake out of the fender that was the dumbest design I've ever seen bunch of dirt and crap in there blowing around getting sucked up by your air intake at least take the end out and blow it out with an air compressor or something but you might be shocked to see how much dirt is actually sitting in there better off just to leave the end of the filter housing open I actually put a chunk of filter over the end as well but every time I've cleaned the sensor and the throttle body she's right back to running like new

97 F150 4.6L XLT Supercab 2wheel auto with 246,000 km saved from being parted out paid $600.00 for it put another 1000.00 into it and she's solid as they come reliable as an anvil and has never let me down I wouldn't trade her for nothing

 

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Had the same problem with my 2002 and had several faulty injectors that only acted up in the heat