2012 ecoboost
I have no problem with power once the motor is going but frequently, after stopping completely, I will press on the gas pedal and the motor just stays at idle for a second, no matter how hard I press the gas, and then takes off. I also notice the tachometer needle moving ever so slightly up and down at idle.
I replaced the plugs with properly gaped new plugs and it made no difference.

It really feels like the throttle is getting a delayed signal from the pedal as sometimes the gas pedal will be pushed half down before the motor catches up then surges forward.

Has anyone had this issue and did you figure out what it was?

There is plenty of power through the whole RPM once it gets going, I already drilled the intercooler and there was no fluid, so I plugged the hole.

Oh yeah, I have about 120K on it

 

I had this issue with a hyundai and it turned out to be a sensor under the brake pedal

 

Seems what you are describing is called "throttle lag". I'd bet either you, or who ever normally drives the truck, is pretty easy on the pedal. These trucks "learn" how you drive, and adjust the engine controls for better economy. I think they get confused sometimes.
What you could try is a KAM reset, KAM is another of our everyday acronyms for, Keep Alive Memory. Disconnect the battery, negative cable first, and let it sit disconnected for 15 minutes or so. Reconnect, positive first, then go for a ride. I think you'll see a difference.

 

Any engine with turbos has a slight delay between foot on the gas and getting power to wheels. Sounds normal to me

 

Could be, but the way it's described it appears more severe than "turbo lag".
Anyway,for 15 minutes of time, why not give it a shot?
Notice OP mentions the rpm doesn't change when he presses pedal. With "turbo lag", the rpm increases, just not as quick with some boost.

 

Its definitely not turbo lag. I mean the engine wont move from idle until the pedal gets about half way sometimes. I've done the battery disconnect on other vehicles to freshen up the response, but I've never had this much of a delay before, other than the hyundai with the bad pedal sensor.

I will try the battery disconnect though. Maybe it has actually confused its self with the learning curve.

That is one thing I hate about modern cars. They should not try to learn your style. The throttle should always move the same way with the gas pedal and the driver should learn the throttle. I hate this about every vehicle you buy now days. Wish there was a way to disable the learning. There should be one controller, the driver. Not two controllers (the driver and the computer) fighting each other constantly.

 

I have the same thing happen to me.
2011 3.5 ecoboost.
No response when pushing down the accelerator.
It does not happen every time.
Seems like I almost have to floor it to get it moving, then it takes off.
Sometimes it happens when accelerating to merge on thruway.
Sometimes it happens when starting from a dead stop.
I think if it were turbo lag, at least the engine should accelerate but the boost might not kick in.
I have had it in to the dealer and they say they can not duplicate issue.

 

Mine was acting the same way occasionally too.

I cleaned the throttle body and Maf sensors (3 of them) and did the battery reset.

It's been a couple of weeks now and I haven't noticed the lag anymore. Not sure if that was the problem but it sure didn't hurt, they were pretty gummed up and dirty (115,000 miles).

Note: use only approved cleaner on those items and not carb cleaner.

 

Agree 100%. You have to remember, people have gotten dumber, not smarter though, at their own discretion usually.
Cleaning the throttle body sure couldn't hurt. Do a Utube search before you do it, there are some, and Ford is one, that you could actually hurt yourself badly if you don't do it right. Something about possibly loosing a finger?