I have a 2004 4.6 F150. I notice that my acceleration is somewhat lacking. I havent run into a problem but it seems like the truck just falls over itself when it gets to 25 mph (This is an acceleration where i keep the pedal at one spot for a normal acceleration from a stop) Then after that it is a really slow acceleration getting up to speed unless a really push the pedal alot further. I know these are all drive by wire. I really dont think there is anything wrong with the truck. I think its just a characteristic. Major parts that have been described by others (speed sensors, TB) with faintly similar problems have been replaced by the dealership under extended warranty because of other problems. I dont really lack in MPG or anything like that. i just want to know if poor acceleration is really a thing with these 4.6s? Also i have asked the dealership twice to check for updates for the PCM and they have told me it has the latest twice. I really need to know would a tuner fix these problems? Or has anyone heard of dead spots in the sensors on top of the gas pedal that would create this scenerio. And could i plug and play a new gas pedal assembly if that could be a possibility? I just think that this truck could have a better acceleration than it does. And like i said it isnt or hasnt been or got me in a problem its just a little annoying that during a normal acccerleration that i have to push the pedal down quite a bit further to get the truck to go on flat gound.

If i punch it to go it is fine, everything else is fine with the throttle and no trouble codes or other problems. I cleaned the MAF, i dont have a K&N, new fuel filter, everything else is tip top shape. I have been contiplating a tuner but dont want to get one if it wont help me.

Does anyone have any suggestions on tuners? (Edge, superchips, etc) I wont be doing a whole lot of personal tuning just looking for something to give me what the stock lacks, and i dont care about a heads up display. Thanks guys!

 

Hi xjcamaro89
After driving a 2005 F150 4.6L for about 2 years I can a test to its above mid throttle weakness. The improvements will be significant with any flash tuner. Its a night / day difference vs what you are seeing/feeling.

Give me a shout and I can give you some more info on what our custom tunes contain....

thanks
Mike

https://www.ford-trucks.com/forums/7...y-savings.html

 

Anyone have a personal experience with this lacking and cure with some sort of tuner one way or anyother.

 

Some here have had luck disconnecting the battery for a few minutes, and allowing the PCM to reset itself.

Remember, the drive-by-wire system is supposed to "learn" your driving behavior and tailor it's operation to what it thinks you are trying to do. Which it seems to have done incorrectly.

So, to put this another way...sounds like you don't like how far you have to push the pedal to accelerate?

Maybe the "problem" is that you aren't satisfied with your power in higher gears, so you end up forcing a downshift...? I don't know, I've never driven one with the 4.6...

 

I have disconnected the battery about 1000-2000 miles ago and let it relearn, but it still feels the same as it did before. And also it does feel like i have to force a downshift to get it to really go. But also like i said before i really think that it might just be a characteristic of these engines that some have said to be real dogs. I'm just looking for some others that have experienced the same problem and have fixed it with a tuner.

 

Well, not trying to be a pain, but I don't think a tuner will solve your problem.

A tuner can do things like advance spark curve for premium fuel, alter shift points, and change the way the computer runs your truck...but it can't unlock a ton of extra power, just by itself. Many claim to have them improve throttle response...but you indicate that you aren't happy until it downshifts...which isn't a throttle response issue, so much as it is an engine power issue.

Short of forced induction, there is no simple fix for you...

 

he can regear with a tuner

that will make the truck a wholly different beast...but it'll most likely cost $1500-2000 for them though



but yeah, the 4.6 doesn't have the gumption for these heavy trucks...maybe in the single cab

 

Ah, leave it to Tylus to think of what I forgot!

Changing your rear end gears to something more aggressive would help, but would be pricey...and would require an adjustment to keep your speedo and odometer accurate....

I had a power problem with my '03...same issue, but with a relatively gutless V6...so I traded it in on a Mustang. Plenty of power, but not 4x4...so I got my current truck with the 5.4......but I'm a little picky!

 

if 2wd, the regear would be relatively cheap...not so much for the 4x4

I have more than enough power...but I still want some 4.56 gears. but they'll run me $2k...and I'd rather run a lift kit for that money


really wish the 4.10 gears were offered for the regular 6-lug F-150...cause then I'd go buy the 2 pumkins and swap 'em for my 3.73 pumkins

 

I'm pretty sure the front end is the exact same 8.8" diff we have in ours, so that'd work up there...

And what's wrong with swapping in a 10.25" axle? Heck...with all that power you're pushing...couldn't hurt!

 

Feel free to PM me if you have any questions.

Scott

 

@xjcamaro89...did you ever do anything?
sorry crazy, never saw your post until it got bumped up to the top

cause then I'd have to get a new driveshaft, u-bolts and maybe even leafs to make a 10.25 fit...and all of that for only 4.10 gears. I could probably install 4.56 for about 1/2 the price of doing a swap

Roush did some testing with the RoushCharger and the 5.4 drivetrain can hold the extra HP with ease.

 

I never ended up doing anything. But the funny thing is, is that about a week to 2 weeks after that thread phased away i noticed my truck really started to come around, like it took a long time, 2000+ miles for it to learn my drving habits from when i disconnected the battery before. And it was running good, unless it was all in my head, all that seamed to be cured. Around the same time i started using gas without ethanol in it, and that improved my MPG a bit. All was good, but then i had to replace my battery , so here i am again, i had the computer reset because of the battery swap about 3 weeks ago, and the symptoms are back, but maybe not as severe. There were a few other conditions that might have affected it as well though, it was a little bit warmer during that time it was running good, than it is now. So i dont know what is actually happening. Maybe my truck just takes a long time to relearn my habits since my daily trips are very short. I dont know. Anyone have anymore thoughts?

 

Never looked at the details, but I didn't think most of the parts were different....

I always thought all configurations used the same method of attaching the axles to the springs...now I'm pretty sure the HD F150s have thicker spring packs...and maybe the axle tubes may be a bit thicker, but I think most of it would carry over.

Now, I know the driveshaft is different, but I always thought it was simply because of the 163" wheelbase. Are you sure the u-joint is different?

J

 

most likely. it does take a certain # of key on/off cycles and mileage

I know my truck was pissing me off something fierce for about 1-2 weeks right after my supercharger install. It had more power, but seemed confused and lacking...I guess is the best way to describe.


then it suddenly got better. much happier now. I've contributed it to the PCM. my battery was unplugged for 4 days, so it was reset and it just took sime time for the PCM to relearn
yep, there are 6 different u-bolts for our trucks. each one is progressively bigger since the axle tubes are larger with each axle...otherwise it's just a matter of lenght between the 4x2 and 4x4

8.8 axle 4x2/4x4
9.75 axle 4x2/4x4
10.25 axle 4x2/4x4