Loss of power going up hill

[jeepmedic46]

My 05 F150 supercab with the 4.6 and 168,000 miles on her loses power on hills. I replaced the air filter. Should I change the plugs? I heard those are a pain to do that they break easily. Could it be my transmission?

 

[Black Dog]

I had an old S-10 Blazer that did the same thing, I had it in and out of the shop for 5 or 6 weeks and the mechanic determined it was the fuel pump. Replaced it and never had the problem again.

 

[Hopeless Diamond]

I had an '06 F150 that would stumble under slight load, heavy load was no problem. Ended up changing the plugs and that solved it. Had the dealer do it as they typically do break. They broke 3 of them if I remember correctly. They're probably the original plugs in there and should be changed, just be prepared for dealing with broken ones (not sure how or where they break so no idea of the hassle involved)

 

[bfdiesel]

I would look at the fuel filter first.

 

[bloodyWEST]

I would look at the fuel filter first.

X2

 

[jeepmedic46]

I will check that out, I just had a new fuel line put in. Would they have put a néw fuel filter in?

 

[98dango]

Fuel filter and upper intake cleaning also help if the plugs need done.