04 F150 Blowing Fuel Pump Fuse

[Nates.Mom]

Ok I'm out of ideas on what to try next with my truck. About 1 month ago it blew the fuel pump fuse, I replaced it and it worked fine for about 2 weeks then blew the fuse again, so I changed it and the fuel filter and it ran fine til last weekend. Last weekend it blew yet again and changing the fuse didn't help it would start and then when you would attempt to take off, it would chug like I didn't give it enough gas (it's a manual) and then die and the fuse would be blown. So we changed the fuel pump thinking maybe it was bad, and the truck ran fine until yesterday when it started blowing fuses again. I didn't have any 20s in the truck so I stuck a 25 in it so I could get it home and it ran fine with the 25 in it. I replaced the relay last night, that didn't help. I checked the fuel cut off and its fine. I need some help!

[jdl]

I'm not sure of litre size of engine? You may have an injector problem? If I was looking at the correct engine info, that fuse serves more than one circuit. Just a thought.

[Nates.Mom]

Its a 4.2 engine... It's the heritage edition.

[jdl]

That fuse only serves one circuit. I'd have to use a gage and check fuel pressure. Some of the national brand autostores used to loan out a fuel pressure gage, if you don't have one. How long since the fuel filter was changed? You have to make sure there is no pressure on fuel lines, before taking anything loose.

[Nates.Mom]

We just changed the fuel filter about 2-3 weeks ago when it first started blowing fuses. It drained "gas" about the color and consistency of coffee... After changing it, the truck ran great for 2 weeks until this weekend when it started blowing fuses again.

[jdl]

I'd have to double check everything that has been done. I'd still want to check fuel pressure. If no schrader valve, it makes checking pressure a little awkward, a proper scanner might show fuel pressure. Could be a faulty fuel pump again? I'd want to check the fuel filter again. Possible faulty wiring connector, or faulty wiring. I can't tell from here.

[Nates.Mom]

So far in consecutive order the truck:
Blew the fuel pump fuse, changed the fuse the truck ran for a week without blowing the fuse. We changed the fuel filter even though the truck still hadn't blown any fuses. After changing the fuel filter the truck ran great for 2.5 - 3 weeks, didn't blow a fuse or anything. Last Sunday, the truck started blowing fuses again and changing the fuse it would idle, but upon putting the truck into 1st and taking off whether you gave it a lot of gas or just a little, it would sputter and die and the fuse would blow. The truck would run fine with a 25 amp in the fuse spot, but if you put the recommended 20 in it blows it immediately. On Sunday we changed the fuel pump and the truck ran great with a 20 amp fuse in it until Thursday when it started blowing fuses again. On Thursday I changed the last possible item which was the relay and this didn't help either.

[Davescort97]

It's said not to put in a larger fuse because it could damage the wiring. IMO putting a 25 in instead of a 20 isn't going to cause any problems.

[Nates.Mom]

Davescort, Thanks for the opinion, I was thinking the same thing, but wanted to see if anyone else was... I'm still looking for ideas on what else could be wrong... So if anyone has any please let me know Thanks