i have a 4.2 with a 5 speed and for what ever reason i have worse gas millage then my dads 5.4, is that normal or is sumtin wrong. also it has no power at all i cant maint tain 60 on the parkway unles im in third, 4 will do it with my foot to the floor and i never had a chance to use 5th yet. is that normal, mabe if i changed the gears in my rear it will work better

 

it sounds like something is wrong with your truck.... I had a 97' 4.2 with the 5 speed and that thing did quite well on mpg. It had sufficient power and could easily maintain 60mph in 5th gear on the highway and inclines for that matter.

 

I can cruise in 5th in mine at 30 mph and I get 15 mpg in the city and close to 20 on the highway. You have a major problem somewhere, are you sure your parking brake isn't stuck on or something?

 

i see your signiture says you have a 3.55 rear end, my axel code in the door jamb says i have 3.05 rear end, and im pretty sure the parking brake isnt stuck on because if i dont have it on for even the slitest of incline(like i couldnt even tell i was on a hill) it would roll away on me. its a two wheel drive 8 ft bed reg cab, and the motor was rebuilt by ford(guy that sold it to me worked at the dealer) rite before i bought it, if that helps, anything thing i should check for, i thought i mite have a dead cylinder but it runs to smooth

 

Even with 3.08's you should be able to maintain speed on level ground in 5th at 35 mph and even accelerate, albeit slowly. I can hold 60 on the Interstate in 5th pulling a fully loaded 5x8 trailer. The difference between 3.08's and 3.55's is not that extreme, you definitely have a problem somewhere. The little old 4.2 has plenty of low end grunt.

 

About all you can do is start pulling plugs and check for funny business on them...

Double over the brakes. Recently, I ended up getting a new pair of front calipers. The passenger side decided to stick and chew up the rotor, but it happened on my way to get maintenance done, anyway.

You won't do much in 5th with 3.08s, since you're basically doing idle ion the highway, but you should run better than a 4 cylinder Ranger with a dead cylinder, that's for sure. Other than a miss heard from the exhaust pipes, that truck of mine ran well (seemingly), otherwise.

 

is it possible my fuel filter can be clogged? in the 10,000 miles since ive owned it i never changed it so who knos if the previose owner did

 

It's possible, wouldn't be a bad idea to change it. Doesn't cost that much and is usually easy to change if you have the clip release tool.

 

I had a 97 4.2 5 speed before my FX4 and it did OK on the highway as long as stock tires were on it. Bigger tires = worthless 5th gear. Gas mileage was always pretty good.

Are your tires too big?

 

Even with totally huge tires and 3.08's he should be able to maintain 60 in 5th, and should not have to floor it to maintain 60 in 4th. That's just too extreme.

Hmm - you may have plugged catalytic converters or somebody stuck a potato up your tailpipe. Collapsed muffler baffles would do it too.

 

my exhaust is flowing pretty good so i dont think anythings clogged, but i checked my air filter and its filthy so im gunna get a new one when i get paid and also do a fuel filter, plugs, wires, clean mass air flow, change pcv valve (let me kno if i should do anything else) but today on my way to school i got it to maintain speed pretty well got 55 in 5th whith very little throttle but my millage still sucks

 

Speaking of junk stuck in a tailpipe... I was walking in to class the other day when it was like -2F outside... and this student's exhaust was plugged up with ice. I saw him start it... it sounded like a loud pop and the car couldn't restart... Interesting crap happens around here. It was a Honda with a 1/2 or maybe 3/4 inch exhaust pipe... it was tiny.