I just bought a 2004 Ford 150 STX 4.6 it has 305 70 17 tires, 4:10 gears, and a K & N Intake and no mufflers with true dual exhaust. IT idles great and funs smooth but seems to have no power to me. Punching it from a dead stop is very dissapionting. It hesitates for about 2 seconds then starts to take off and it doesnt do that very well either. Its hard to explain. It seems like it wants to go but its held back by something. I was wondering if maybe its a gearing issue, or something electrical... it takes for ever to even get to 60 mph. please help!!

 

Hi 04nightprawler
About 80% of the issue is the factory PCM calibration. Seriously, look into some sort of flash tuner. My personnal daily driver was a 4.6L for 2 years and in stock form it was very lacking. Email me if you have any questions.
Any flash tuner will help make it come alive.

Merry Xmas to you
Mike


ps Welcome to FTE too...

 

I would check your MAF sensor and clean it ASAP since it has a K&N on it, it could be gunked up and throwing off your AF ratio. But i know sort of what you mean, my 4.6 is like that as well but ive check over the truck extensively and have come to the conclusion that its the way the truck runs, and im looking into a tuner, just my thoughts!

 

it's the small v-8 paired with a heavy heavy truck

sucks, but tuning can/will help. somewhat surprised you have issues though. you said she has 4.10 gears with 33" tires right?



another thing, these trucks have an adaptive PCM controller for the tranny. try unplugging the battery for 30 minutes. This will clear the learned stuff and start off fresh.


just be aware she will run slighly 'strange' for a few days until the PCM adapts again.