I've been struggling with this for over a year now, and as yet no breakthrough. I'v followed advice from previous posts and have eliminated possible "causes", but not solved the problem.

Summary: 2011 F-150 5.0 ran like a scalded cat when I bought it used with 106k miles last year. About 6m in I started to notice it wasn't quite as much of a tiger as when we started. I got a powertrain warranty so off to the dealer we go. Verdict? It's my imagination.

Forum posts, and a little $$ thrown at it, got me a new MAF, new coils, new OEM plugs (gapped properly). FRP tests fine. Compressions are near-identical on all cylinders (115-118). Tranny was serviced at 66k and again after I got it at 115k.

Symptoms when unloaded are: A lope when I press the accelerator, then it shifts to second and immediately to third. Unless I drive like I'm on the track, this trucks computer does whatever possible to keep it about 1800rpms. It takes *extreme* throttle movement to get it to wake up. There are two modes: oozing away from a light like grandma or begging cops to chase me down and give me a ticket. PS, (I've tried), there is no circumstance where this truck will ever, ever lay down event a tiny shred of rubber. Can't do it.

Second problem: this truck runs like crap at 1800 rpms. It "misses", but there are zero misfires in the mode $06 data. I even rigged up a piece of allthread as a makeshift way to hold the rpms at 1800 in park. when I do that, it bounces between 17-1900 back and forth. If I dial up to 2000 it'll stay steady. It'll stay steady at up to 1700 too, so this "not a problem" issue happens between 1700 and 2000. Which as I said is exactly where the computer likes it to be, which sucks.

Final problem: I tow a travel trailer (5500lbs fully loaded). (I should say I'd "like" to tow my 5500lb trailer.) When under load, this truck cannot maintain speed on the slightest of grades. It's severe - I need 3rd gear and at *least* 4500 rpms to get it to move. It *will not* make 60mph on level ground, period. Max speed level ground is about 55 in 3rd gear pushing redline to stay there.

I'm at a total loss. I've had it to three dealers - all three tell me I'm imagining things. I simply don't have time to load up the trailer and pull the whole rig to a dealer and leave it for a week for someone to drive it and prove I'm not crazy.

The OBD scans are clean. Fuel trims are good, all sensors are good. Zero misfires in the mode $06 after even long drives.

Dealer #3 even convinced me to "upgrade the ECU" and that would fix it. Guess what, no joy. And no amount of whining will get a refund since they claim the ECU upgrade was necessary and required to fix several TSBs. Aargh.

Bottom line? I have a truck which cannot do its job and am surrounded by people who think I'm the crazy one. I'm not an idiot, just short of any good advice or suggestions beyond what's already been tried.

Please?

 

It sounds to me like your throttle position sensor could be faulty. But keep in mind that if you do try that, that you will need to do a throttle relearn procedure on your truck. And one of our resident Ford mater techs should be able to help guide you to doing that procedure.

 

Thanks paredneck. Anyone have that relearn process? Or I suppose somewhere out there must be a guide to troubleshooting the TPS (since it's not throwing any codes).

Off to the google machine again.

Any other thoughts out there?

Thanks.

 

I'd also check your PCV tube to make sure it's no clogged. Very simple to do on these engines. And that valve above the throttle body...check it to see if there is vacuum. If so it has failed. A cleaning of your throttle body may help also. Pretty simple to take it off and clean it. 10 minute job.

 

WXboy, thanks. I neglected to mention I have cleaned the TB and put in a new pcv a few weeks ago. I am however very curious about "if there's vacuum it's bad". Can you give more details about which valve to check (and what it's called so I can research)?

THANKS

 

Here's a video that explains it.

 

thanks for the link. I checked that valve and it seems to be working fine.

Im afraid this thread is dead again with no more activity. Any admins have suggestions for me to get better responses? This is my third attempt on this topic and while I get good answers I haven't yet hit anyone who's experienced this or is a deep expert.

Honestly im shocked no one has mentioned the transmission. Isn't there a list of things that could go wrong with the tran that would cause no power at the wheels or sluggish shifting?

 

Well, the fact that the dealers are all saying it's normal to have a truck miss around 1,800 RPM and have no power is baffling. It sounds pretty severe in your first post, and if so I cannot believe that the dealerships would all dismiss it as normal. Have you tried an independent shop? You'll have better luck there.

As far as the transmission goes, there was a TSB on the 6R80 for failure of the "molded lead frame" inside the trans. Typical symptoms are erratic shifting and the possibility of a 6th to 1st downshift while at highway speeds which is what prompted the campaign to fix affected trucks.

Since your throttle sensor and all engine diagnostics are fine, possibly the trans is the issue. Unlikely, but possible.