I've done several pedal to the floor launches with the diff lock engaged and they are great. What I have not yet tried was powerbraking because I was told it would not work due to BOA programming on the newer trucks. I'll have to try that out ASAP. Drove the beater to work tonight though, so it will have to wait until tomorrow. Thanks for the heads up. I'll see what happens.

 

To "BlackBeest" and others:

I did use the word "lag," but I should have done a better job writing. I did not mean to suggest "turbo lag." The "lag," or delay, I referred to is the extra time it takes to move (when driving "one-footed") the right foot from the accelerator to the brake---compared with the lesser time it takes if one were using a two-footed approach. So, I am driving two-footed to save time and add convenience/ease---but, to restate, I try not to touch the brake with the left foot at the same time I am touching the accelerator with the right foot.

If someone is against "two-footed" driving, okay----but, what I do is "alternating feet" driving! So far the instances of experiencing "dead or delayed throttle" has decreased considerably---and will continue to decline the more it becomes a habit.

 

Just for grins, try driving around in tow/haul mode for awhile, tell me how that works out for you.

For the life of me, I can not recreate the symptoms I've gone back now and read in this thread, and I've almost accidentally done everything some of the others' have reported.

At first after getting used to my truck, and the "delay" in power delivery vs. pedal input (again, nothing I perceived as "broken", to me, the engine and transmission were working within their design), as I'd sometimes want to spool up the turbo and zing out into traffic, I'd powerbrake/stall it up a little, all the time: while turning left/turning right, from a stop, or a 2-5 mph roll, and the truck never fell on its face....

But what ultimately got me to the Tow/haul mode was the transmission behavior while driving. The trans just seemed too eager to get to 6th and clock out for the day, so knowing what I know about the usual/other vehicles' "tow modes", I tried mine, and it's been a night/day difference in drivability. Power delivery, throttle response, downshifts, even the engine braking involvement has been a welcome change. Takes a little getting used to, but it's how I'll drive, and expect my truck to, from now on.

 

Since I don't hot rod my truck very often, I didn't remember to try BOA until just as I was stopped to turn into the parking lot at work this evening. Powerbraking DOES work on a 2014 after all. I can't remember exactly where I read that it wasn't possible, but it seemed to be somewhere "official" - like my owner's manual. I'll have to look sometime later to see (not that it matters at this point since it is possible after all). Maybe I dreamt it. Now, I'm looking forward to an actual boosted launch from a light sometime soon.

 

I am new to this forum and after searching the web for the accelerator problems I am having, I came across this forum, which by the way, is outstanding. I just bought a '14 F250 4X4 with the 6.7 diesel. So far I am pleased with the way it looks, handles, etc., but I started noticing something wrong with my acceleration shortly after I bought it. Funny, I didn't notice it when I test drove it. My problem seems minor in comparison to some of the more serious safety-type issues, but it is annoying to say the least. When I come to a complete stop and then accelerate there is a noticeable "flat spot" that only lasts a fraction of a second and then it takes off. I cannot attribute this to turbo lag because it happens so quickly. I seem to notice this more at times and then less other times. It is nothing that is a safety issue, but is always there in my mind. I am convinced all vehicles are made to accelerate smoothly and this truck should be no different. I took it to the dealer (one of the best diesel-oriented dealers in Texas) and the tech drove it and then tried to pull up any codes, but none showed up. I talked to him afterwards and he said that everything was normal and within specs, and he could not feel what I was feeling (gee...what a surprise). He said that what I'm feeling could just be something that is "unique" to this truck, but I'm not buying it. It's like so many others experience "after the sale" from dealers...not really concerned with a less than helpful attitude. I don't know if this problem is anything like others have experienced in the '11's, but it annoys me all the same.

 

Im just throwing this out there cause I read something on here before about delay in acceleration.Somebody said that if you happen to be a "two footed driver" one foot on brake and one on gas there will be a slight delay in acceleration.Cant remember the reasoning.But if you drive normal with only one foot then forget what I said.

 

The owners manual or Diesel supplement (can't remember which exactly) calls it BOA - or brake over accelerator - and says that it is a safety system put in place to disable the throttle when the brake pedal is pressed to prevent unintended acceleration as was supposedly the case with the Toyota Prius several years ago since we have throttle by wire and extremely powerful engines. However - as was pointed out to me on this forum previously - we still have the ability to do a boosted launch, by simultaneously holding both pedals down, so it really makes no sense to me. After reading that, I tried it and found it to be true.

 

I just wanted to post an update.
My dead throttle issue was definitely due to BOT (brake over throttle).
My dead throttle issue has occurred several times over the past 6 months, and every time I had my left foot on the brake. I must say I do not like the BOT feature, but my truck runs flawlessly, and I am very happy with it.

 

I have a 2013 6.7 and mine does the same thing from a stop hit the pedal to the floor and it takes about 3 seconds before it moves then it immediately sets you back in the seat as if i was drag racing, but then when i let off it takes 3 seconds to to come off full throttle and it gets scary when it's stuck at full throttle even when my foots is off the throttle and on the brakes waiting to stop it.

 

I drove a 2020 F550 6.7L for 6 months and had these same issues. Truck had a PTO powered blower/vac, there were leaks at the PTO (I was never underneath it) and the trans would become low on fluid then would slip going around right hand corners.

Then it developed a complete loss of power, Tach would drop to 600 instead of going up while trans slipped. This would also happen in right turns but also while going over bumps/potholes... Most of the right turns were also bumpy so I figured it was the bumps causing something and after reading this thread, perhaps the bumps cause a "brake applied" signal somewhere???

I found that with a press of a couple of buttons you can turn One truck into Two trucks. The first truck runs like a dead dog and the other one runs like a normal truck. The two buttons left of the 4-way Flasher (2020) button (turbo brake and traction control) Press each one once after you start the truck and drive in a normal truck all day long.