I recently got a little single cab short bed v6 5 speed truck who's engine has recently been rebuilt. The truck doesn't run awful but it doesn't run as well as it should. For example the other day I was on the highway cruising in fourth gear going around 65 and the truck just started slowing down. I watch as it went from around 65 to 45 then decided i should speed up again and shifted down into third. To me it feels like it isn't making enough power to pull in fourth gear. Also when i was teaching my girlfriend how to drive a manual the other day she locked out the steering wheel one way and the strain it put on the power steering pump almost stalled the engine. I am very new to these trucks and I've never even worked on a v6 anything before so any help would be greatly appreciated!

--EDIT--
Forgot to mention my truck is a 1999 f150

 

At 65 I would have been in 5th gear. The 4.2 isn't going to win any races and if it wasn't pulling enough in 4th at 45, try third gear.

She locked out the steering wheel while it was off? I'm not sure I understand what you meant by that. Why would she turn the wheel while it wasn't running anyway?

 

Any OBD2 codes?

Check your cats for blockage.

 

A really dirty air filter will cut down the hp too.

 

My OBD port is broken and so i could not read the codes if there were any. I'll definitely check out the air filter and cats though. Also i know the 4.2 isn't a super high horsepower engine but what i was saying is that it couldn't even drive in fourth or fifth gear for more than a few miles.

 

Check the fuse for the cigar lighter, replace it if it is burned. The OBD port and lighter are on the same circuit.

 

I pulled the air filter and it isn't all that dirty, I'll go ahead and replace it but i doubt thats the root of my problem. Also i drove the truck a few feet just now to get it into the light and when i stopped it was making this hissing sound from somewhere close to the passenger side exhaust manifold, almost sounded like evaporated water trying to escape from something. This isn't the first time I've heard the sound either

 

Could be water from the AC dripping on the exhaust. Not sure what's happening, but my 4.2 has always been pretty peppy with a 3:55 rear end and auto trans. Towed a ski boat many times with no problems.

I'd check fuel pressure, also change the fuel filter, but read up on how to release pressure first, so you don't get a face full of gasoline. Does it overheat going up hills? Sign of a clogged fuel filter.

 

I figured it should be pretty peppy, especially with a 5 speed transmission. After all it does make over 200 HP. and i have a new fuel filter I'm going to install as soon as it stops raining for a few minutes thanks for the tip about releasing fuel pressure, didn't think about that one.

 

Sounds like it could be a major vac leak at the vac reservoir, or one of the lines going to or from it. The reservoir is on that side by the battery. Could be the cause of your problems too.

 

Alright sorry its been so long but i have an update. I replaced the fuel filter and noticed a pretty big power increase, but the car will still only go about 70 in 4th and 55 in 5th on flat ground. Cut out the cats and all it did was make it louder, i think i may have a bit of a exhaust leak, need to clean up my welds a bit. But the big deal is that my uncle got a code from it on his decoder and says its saying "Leaking intake manifold" what does that mean and could it be the source of my problems?

 

What was the exact numerical code?

 

I don't know, I'll get him to read it again next time I see him, hopefully tomorrow

 

I was having similar problems with my '99 4.2L F150 i found vacuum leaks at the rear on the passenger side valve cover area, vac lines. There are so few on this engine. There is an Elbow there that gets real soft and cracks. I actually used an old spark plug boot to repair it. It wasn't sold separately only the whole set. I'm low buck , so there's that boot still on there. In the same area there is some valve I could never see, I had a shop code out the truck and it threw out lean intake yada yada. Same as the vac leak. Well it turns out there is a small plastic link that a metal arm hooks into, kinda like on a door lock. They replaced the whole thing for that, but it runs great.
Another area, front center of intake on bottom side is a trouble area. hard to reach, vertical tubing 2-3" long but it should be checked if getting lean codes.
Sorry about the long reply. Just wanna help.
Good Luck
Timathie

 

Look for one of these:
http://s2.photobucket.com/user/kekah...00117.jpg.html
I had one bad in the front of the upper intake and a piece of hose bad in the rear (near firewall).
Also - theres a vac line by the battery that's always a possibility.

PCV line (just for reference):
http://ww2.justanswer.com/uploads/th...211345_pcv.gif