i have an 02 fx4 with a 4.6. for the past 3 weeks i have been having some problems with starting it. if i let it sit for over a few hours it starts fine. but if it sits for under 2 hours or so, it has problems starting. it cranks over great but just wont start. i think it may be a fuel problem. the fuel filter is about 1.5 years old. if i finally does start, for the first few seconds, it sounds like it is chugging for gas and barely stays running. does anyone know what this could be? also i have noticed a large decrease in mpg and horsepower. thanks for the help in advance! oh and my truck has 91k miles on it

 

I would replace the fuel filter and if that didnt clear it up I would start diagnosing the rest of the fuel system starting with a pressure test.

 

sounds like fuel filter to me. Pump might be on its way out maybe, try filter first tho. its a cheap fix.

 

Hold your foot on the floor, turn the key, and start it. If it starts right away, lift your foot and see if it keeps running. If it does, your fuel injectors are leaking down after shutdown.

 

how long do fuel filters usually last? i have had the one currently in the truck for about 1 1/2 years. thanks

 

Fuel filters are generally good for 30k, but all it takes is one tank of really crappy gas to plug it.