Engine dropping to idle at speed

[Hbar]

My '15 Expedition has begun randomly dropping to an idle at any speed during various levels of acceleration. The throttle becomes totally useless. I can turn the engine off and back on and it will run fine. The first time it happened, the dealer replaced the throttle body. I recently took it in and the dealer claims they can't find the issue without seeing it happen. Ideas?

 

[Timo2824]

Your throttle body will need replaced, it's loosing it's position and the safety is to return to idle position.

 

[Andy Rubalcaba]

I could be wrong, but since they replaced the throttle body already then my next thought would be to replace the crankshaft position sensor? give that a look.

i don't think it would be idle control valve, i've had plenty of that issue on my old land rover, which acts a bit different ( high revs or nearly stalling out ).

 

[Goofy173]

Also this is accelerate by wire. If it loses connection from the gas pedal to the computer, it will drop to idle. First reset the connector at the gas pedal. I had this happen when I added an accelerator controller and didn't get the connector completely snapped in and it popped off.

 

[YMRacing]

I'm on my third throttle body. Yah, they told me they couldn't find any codes because they cleared each time I shut it off and restarted it. I hooked up my OBDII reader and left it in. I then had the codes each time it happened. I have a 2017 with 35k. All have been replaced under warranty, first in WI, second in IL, 3rd in TX. I now carry an extra one with me.