Hey guys,

I have an 01 Supercrew with a 5.4L and about 95k miles. I noticed last summer that the truck was really down on power. It seemed to get better in the winter but now that we're back in the throws of an AZ summer the truck is really weak again. The motor seems to run smooth, no miss, no rough idle, it just doesnt have any power, especially on the low end. I've replaced the plugs about 8k ago but other than that, the truck hasn't had anything done to it.

Any ideas where I should start looking for the culprit?

Thanks

 

Sounds like a problem I have. Runs way better in the cold and in summer no low end power. I think its my exhaust. it has leaks and the cats are bad. Here's what the Chilton says it could be... I'll put the ones it could be only because there's a big list
Air filter dirty
ignition coils bad
fuel filter clogged
Egr isn't funtioning properly
Vacuum leak at manifold or hoses( defintely check these)
dirty or clogged fuel injectors
restricted exhaust system
Hope it helps I don't know as much as a lot of people on here.

 

yeah i have that problem a little too.. its way better in the winter, then in the warmer months the power just seems gone. it also seemed a little hesitant sometimes and unnaturally jumpy at others. i cleaned my throttle body today and that fixed the hesitation and jumpiness issue. it helped with the power a little, but the problem is definitely still there. i think im gonna clean the MAF sensor tomorrow, then use some of that techron and see if that helps any. then the fuel filter if none of that helps.

 

You can try unplugging the maf sensor. If that helps you have a bad sensor. Check the filters and run injector cleaner thru the system. You may have to take it in to clear the check engine light after unplugging the MAF sensor unless you have a genreic tool. Basically you're fooling the computer by taking the MAF out of the equation which puts the computer in a default mode and sets a base value for the air. Hope this helps!

 

It might also be that in the winter you are getting good cold dense air. and in the summer especially in az all you are getting is really hot dry air

 

i think its just the fact that in the summer the air going into the engine is alot hotter and the air temperature outside is alot hotter causing the engine to not run as powerful. I have noticed the same exact problem on my truck.... thats why when i have done my 0-60 time it has been in the winter