A recent problem with my 2005 F-250 (5.4l) has got me stumped with little clue where to start: The engine shut off while driving and will not restart. There were no warning signs (check engine light, misfire, noise, etc) it just shut down like the key was turned. The engine cranks fine, has no troubble codes, and all the accessable fuses and relays are ok. I cannot however hear the fuel pump prime when the key is turned on (hitting the tank does nothing) and since there is no schrader valve I cannot verify fuel pressure.

Does anyone have any ideas or had similar experiences? Something must have tripped and interrupted the fuel pump power. Security system, ignition, pcm? Ive tried re-programing the keys and resetting the memory by disconnecting the negative battery cable. No change. Its only got 50k miles on it so I really doubt the fuel pump itself is shot. Thanks in advance for any help you can offer.

 

I had the fuel pump on my 2008 250 5.4 fail when the truck was fairly new, but it gave a little warning like not accelerating at 45 mph or above, and it acted up for a day or two before failing. I think the low fuel indicator light may have come on as well. Your problem sounds electrical, check your fuses.

 

There is an inertial switch that shuts the pump off if you get in a collision. I believe it is located on the passenger side foot well. There is a little button-switch to push to reset it. Might try that first.

Apart from that, you should test for power at the fuel pump to see if it is a power delivery problem or a dead pump before just replacing the pump.

Good Luck!

 

Thanks for the replies. I checked the inertia switch and it seems ok, I even tried bypassing it to rule it out. No change, no response from the pump. Might be worth testing for power to the pump but getting at that harness for a simple check is next to impossible.

 

Well, start by testing for power at that switch. It's not as definitive as testing at the pump, but it will tell you if the computer and wiring are good up to that point.

 

I have a couple of inertia switches go bad and not send the power thru them or reset. May check for that but I think I would check at the wires headed into the pump first and work back to it.

 

Ok, so I unplugged the round four pin connector from the fuel pump. I have 11.11v coming in from the trucks harness with the ignition on. I then ran 12v directly to the power wire on the pump and got no response. Think this confirms a bad pump (at only 50k miles?)?

Oh, and the truck will fire and run on ether.

 

If you put power on the pump and the pump still no worky, then it sounds like a bad pump to me!

 

Yeah I guess its pretty obvious after that test... ran 14.4 (from another vehicle) through a jumper right to the yellow power wire and.. nothing. Even tried it grounded out, still nothing. Even the old "smack the tank with a big mallet" didnt get a reaction from it.

I just didnt want to dump the tank and find out something else was the stoping it from running. What makes me even more suspicious of the pump (aside from the miles) is that just last Friday the fuel pump went on my girlfrieds Grand Am... two pumps in one week? Got me thinking Im cursed, lol.

 

I replaced the pump on mine after the dealer f'd it up twice. Be careful not to get the pickup sock folded underneath when you put it in. The pump and float assy. come all in one piece and cost about $500.00 from the dealer. Jack the truck up on some jack stands on the driver side first to give you some extra hieght and you will have to take the filler hose and vent off first before you drop the tank, once you let it down some the you will have to take the other hoses loose and maybe the wiring harness. You can tilt the tank torward the driver side to access the pump assy. if you don't want to remove the whole thing which involves lifting the truck pretty high. Just take a hammer and screwdriver and turn the retainer ring ccw about a half turn and it will lift right out. Be careful to put the o-ring seal back in place when you re-install it. Also make sure you don't twist the internal wiring harness the wrong way and keep the float arm from going up all the way like the dealer did with mine. I used a floor jack under the tank with a 2x4 to spread the weight out because the tank is plastic [yours may be metal] and it only took about an hour it is not too hard. If you have any questions feel free to ask, hope this helps.

 

Thats a pretty dang solid description, thank you. I had also tossed around the idea of just taking the box off (I had a friend off to help lift it). Seems like the six bolts and two fender braces would be almost less work than trying to tip my (full of course) fuel tank out. Anyone ever try it this way?

 

I think in the long run removing the bed would be more work than dropping the tank, and the possible complications from removing the bed like dropping or damaging or scratching the paint. I used a jiggler siphon hose to drain the fuel tank before I droppped it. The hoses except for the fill and vent hoses have quick disconnects on them, you have to push the button on the fitting to release them. When you put the fill hose back on make sure you dont catch the inside liner of the hose on the tank fitting and restrict the hose the dealer did that to mine also. I think you would have to cut the wiring harness for the lights if you removed the bed. If you are patient it is not that hard to drop the tank.

 

I'm going to second the idea that removing the bed may be more work. The real unknown is the bed bolts themselves. If they break free right away, removing the bed isn't bad. If not, you'll go through a number of torx bits before you decide to just grind the heads off. Then if you replace the ground-off bolts with good ones from Ford, they're pretty expensive. In fact, people have said on these forums that the bedbolts are "torque to yield" so I suppose in theory they all should be replaced if removed.


Anyway, you avoid these issues if you drop the tank, and certainly if it can be done in an hour or so.

If you really want to go through the bed, at least see if you can break the bedbolts before commiting to that approach.....

 

Well, you guys make a good case so I think I'll try droping the tank first. The truck has a bedliner in it too so that would only add to the labor of removing it. Probably gonna get at it tomorrow night. I'll let y'all know how it goes. Thanks again for all the advice.

 

Just give yourself enough hieght on the jack stands and it will make the job easier. Remember to be patient, it goes a long way. Good luck, let us know how it goes.