Hi guys, been a while since I've posted...

...So I recently bought an '04 F-150 crew with the 5.4 and about 70k miles. Very soon after I bought it, I noticed a hesitation accelerating from a dead stop. It starts to creep forward, then suddenly the tires almost peel out. If any of you have driven diesel trucks, this hesitation reminds me of a truck with horrible turbo lag. When entering an intersection when there are cars coming, I'll try to give it a little snot to get through in a hurry, but it hesitates for a second, then the tires almost always break loose.

Also it may not be related, but I've owned and driven a lot of 1/2 ton trucks with a V-8. I've known a ton of people that have had the 5.4 motor, and everyone has said that they have great power, but I've never owned one. my company truck is an '09 chevy with the 4.8? motor (the small V-8 that GM makes), and I always though the truck was gutless compared to others, and many people agree that those motors didn't have much power. My new-to-me F-150 doesn't even have the power that the chevy does, which makes me think that something is wrong.

Once the truck is moving, it feels as though I am hauling a REAL heavy load. For you guys that pull trailers, you know that feeling- real sluggish, basically telling you that the truck has to work a lot harder to do everything. That's what my truck feels like.

Like I said, I'm not sure if the two things are related, but while searching through the sites, I've heard a lot of what-ifs so hopefully you guys could shed some light on the subject. Thanks.

 

By the way, this truck idles smooth, and otherwise seems to shift smooth, although at 55mph, if I let off the gas for a second, then push back down on the pedal, the truck will give, what I would call, a hard shift.

The problem with the hesitation seem to be both in OD or not. I have manually shifted into 1st gear, and it doesn't seem like it hesitates, but there is still that sluggish "hauling a heavy load" feeling, and it also seems to do it in reverse.

I bought this truck kind of far away since it was (or at least I THOUGHT it was) a good deal. They offer a 6-month powertrain warranty, but I would rather try get get some answers and hopefully do something about this locally before I make the long journey back to the dealership where I bought it. Thanks!

 

Try spark plugs and a new maf sensor

 

Check for codes. You can can have codes stored even without a CEL. You may have a throttle position sensor or similar issue.

 

Ok I guess that sounds like a good starting point! I wouldn't think that those items would cause it, but that's why I love this site, I get the opinions from the millions that have already faced similar issues!

 

Parking brake stuck "on"?

 

Does the truck have a factory set up or larger heavier tires? This caused my 150 to feel like it had no power until the gears were swapped.

 

I have no idea what the original size of tire was, but it has 285's on it (BFG all terrain). I wouldn't be suprised if that is larger than original, but I wouldn't think it would be big enough to cause a dramatic change.

As far as parking brake stuck on, I know it's not engaged, but if it were stuck, how would I easily find out? the idiot light isn't on in the dash. I have had vehicles with sticking brakes, but they were on the front, and caused the vehicle to pull. I'm not sure if the rear sticking would cause it to pull to one side, since it isn't on the wheels that steer.

I now am in a mad scramble to try to resolve this within the next few days. There has been a death in the family, and I may have to drive my truck and enclosed trailer about 13 hours away to help clean things up. Definitely not the time frame I would have preferred, but death does not wait.

 

Sorry to hear about the loss. Hope you get this problem solved.

 

So I took it to the local ford dealer and took the guy on a drive and let him drive as well. He says he doesn't notice it, and the truck has as much power as his personal truck. He more or less refused to do any work to it, and said if plugs were going bad or MAF sensor, it would have check engine light.

I will go ahead and take this truck on my long journey, and when I get back, probably change these parts on my own, just to rule out anything. But if the guy at the dealership is correct, and this truck operates like it should, then I am extremely confused as to why so many people bought this motor for so many years.

I would probably look into some performance upgrades to give this thing more response, but I'll make sure it's not broken first.

 

Something is definitely wrong with it. Even my 4.2L V6 is peppy at all times although you have to stir that gearbox! The hesitation/snapping to full power sounds like a throttle position issue. In fact, all of it does.
On the parking brake, simply stop the truck on a slight incline and put it in Neutral. Release the service brake and see if it rolls. Assuming it does, now hit the parking brake and it will stop. Release the parking brake and go about your business.
The hesitation could be something as stupid as a sticking throttle plate because of a dirty throttle body. Take the air intake hose off the throttle body. Have an accomplice turn the ignition on (do not attempt to start engine!) and floor the gas pedal while you observe to see if it immediately flips wide open. I'm not sure this will work due to different systems in different vehicles but it should. If you see a lot of black gunk in there, take it somewhere and get a cleaning done on it.
Find the Mass Airflow sensor behind the air filter. See if it is visibly dirty or even has something as innocent as a piece of spider web on it. They make a spray can cleaner for it - avoid touching the wires except with the spray. While you're at it check the air filter and the cold air intake snorkel to make sure the airway is open.

 

Well I made it home safely from my long journey. I drove from north central PA to just outside of Nashville, TN. I pulled my 6x12 single axle enclosed trailer empty, and brought it back full.

If any of you know the terrain on Interstate 81 going through Virginia, you know that you are up and down on the hills. Not HUGE mountains with runaway truck ramps, but but hill nonetheless.

Basically the entire trip out, my truck was starved for power, even on the relatively flat areas. On even the slightest incline, the truck would have to shift down to maintain the speed. For most of the trip, the speed limit was 70, and it was all I could do to maintain that. The overdrive was off, and for most of the hills, it was revving high at over 4k to climb the hills.

I hand calculated my mileage throughout the trip at each fill up, and I consistently got 7.5 MPG with the trailer empty. I don't know what the trailer weighs, but it's a light duty trailer, like most single axle trailers are.

Once I got to my destination, I was disgusted with my lack of power and crappy MPG's. I was extremely busy while down there, but as I was passing an Advance Auto, I decided to pick up an air filter, even though I never inspected the one that was in there, but I figured it only takes 5 seconds to change, so it wouldn't hurt. The original one wasn't real bad, but I was desperate for anything that would help.

Incidentally, on the way back with the trailer loaded (full size motorcycle, 2 dirt bikes, and about 500 lbs of random stuff) I still didn't have much power, but got almost the exact same MPG's, which was surprising.

I've hauled enough trailers with 1/2 ton trucks to know that even an emtpy trailer will cause you to lose some power and fuel economy, but since this trip was about 15 hours one way, I was filling up about every 160 miles, and I think I had to fill up 5 or 6 times each way, I spent about a million bux in fuel.

Now that I'm back, I'm going to start nickel and diming it, changing out one part at a time in hopes of fixing this issue.

 

I definetly second the idea of it being your tps. They usually go bad if youve ever had a dead batterie

 

Bad TPS would not account for the bad mileage, and that is really bad. I was in a band for years that pulled a 23' trailer loaded full with speakers, amps, lights, wire boxes, mic stand boxes, etc. - heavy stuff. We pulled that with a 2004 Chevy crew cab, dualie, 4x4, 496 CID with Allison trans. And we got better than 8 MPG. So something is definitely amiss in the control of your engine.
The 'shotgun' approach is always the worst approach. There's a lot of stuff you can replace before you finally hit what's wrong with it. First, clean the MAF sensor.

 

Someone correct me on the CEL/code thing. Just because there is no CEL does not mean there are not codes stored--is that correct?

TPS, MAF, anything in that area that's talking to the engine computer is a suspect. Even a temperature sensor that's telling it the engine is cold will cause a rich mixture and lead to poor fuel economy.