Hey guys.

I have a 2008 XLT 5.4 with 77,000 miles. When I bought the truck back in Jan it ran great and you could feel the power of the triton on your foot. Since then it seems like I have lost some power. I have to get to 2000rpm to accelerate(I feels like I am driving a semi!) When I get to 2600rpm I can actually accelerate like it used to, but for some reason it seems to high to get that.

Is this about normal for anyone else? I don't think the plugs have been changed on this thing so I plan on doing those this weekend. I just changed the fuel filter and put in a K&N drop in and I haven't seen any difference.

Any ideas or thoughts on this would be very helpful. Maybe it is normal and it is just me and want to accelerate faster... Help please!

 

First question, is your CEL on?

Second, if you actually have to get to 2K to accelerate that sounds like a tranny issue, maybe some more details could help.

Third, and more so an FYI - until you get a programmer and get away from the factory tune, the electronic throttle limits WOT until a given RPM (I dont remember the exact value, think around 3K).

Another thing is, I don't know what other vehicles you drive on a daily basis, or what you drove prior to this truck, but you may have gotten accustom to the truck. What I am getting at, when I first put the programmer in my truck I was amazed by the change, now its just normal - not so impressed anymore. If I went back to stock for a while and went back to a better tune I am sure I would be excited again.

 

My CEL is not on and I keep checking to make sure it hasn't come on.

I can accelerate at any RPM, just nothing like I think it should unit about 2600rpm, so I don't think it is a tranny issue... but maybe need a tranny flush and filter change? The previous owner put on a lot of miles in a short period of time so maybe that is what I need?

As far as a programmer, are there any suggestions? I am not too familiar with them as every vehicle I have had has been stock without any computer mods.

Really my main issue is that it feels sluggish and I am just reaching out to see if this is normal for 5.4s or do I just a full tune up. Thanks for the help.

 

Clean the MAF sensor and reset the computer (disconnect negative battery terminal). Especially since you added the oiled air filter.

 

Sounds like a good place to start. Any other ideas?

 

VMPTuning.com

Best tuner I have used ..... Justin at VMP has tuned my 3 mustangs, a sport-trac and now my F150.

 

Sounds like your torque converter might be staying locked up. That would hurt acceleration below the range you're discussing.

 

i agree with all of the above and im not trying to start any trouble, but ur talking about trying to get 6000#'s of steel moving. i personally (along with others) think the engine is undersized.

you may have some legitimate engine/tranny problems, you may not.

then again, it may be a novelty thing like mdhawkin says, and the fun and power has worn off and gotten you bored.

you could have a stuck caliper.

imo you sould b more concerned with the gas ur sucking back getting it moving, then with how fast u get up to 70.

edit; and for the record, when i get on the highway im pushing 3500/4000 rpm to get my *** up to speed. (then again i hate merging below the flow)

 

I agree completely, it's a big truck and it could be just me trying to get going faster...

When I first got it the transmission had a hard shift from first to second so I added some Lucas tranny additive. I have used this product on a lot of vehicles and never had any issues with it but I am wondering if that may have caused this problem? Clogged the tranny filter? Any thoughts on this?

 

Lucas tranny additive should only be used to keep a sick trans working for a while longer. It's no good for a healthy tranny.

 

Well I went to a local shop and had them do a full fluid exchange for the transmission and change out my rear differential fluid with adding in the friction modifier(no more studder step!!). Both are full synthetic. The tranny and diff feel a lot more solid which is great but still running into slow acceleration.

My next step is have my plugs replaced. I asked the shop if they would let me change the 4 easy ones and let them do the 4 harder ones and they said yes! Save quite a bit of money that way! If you guys have any other ideas on this acceleration issue it would be much appreciated. Thanks guys