Engine surging

[Chickensandwich]

2018 eco boost PIU, 83k. I’m getting surging issues. Before it’s mentioned, I looked at the other posts.. so my issue seems to be just a bit different.

It surges, high speed and definitely low speed. There are no engine codes popping up, it doesn’t go in to limp mode, it doesn’t stall. It seems to affect the transmission. I would guess it surges right at the shift point and causes the transmission to hunt a lot and causes issues. I read about a throttle body issue, it makes sense, but I thought they fixed it. Is this still an issue?? I don’t have a tune on it, and use regular gas.

The explorer recently had brand new motorcraft plugs put in, a new fuel injector, all turbo tubes replaced, and the engine was carbon foamed out by the dealer. These were done in the past and not due to this issue, but i thought it may be relevant.

Is this still most likely a throttle body issue?

 

[texsn95]

Check to see if this small hose came undone. I did plugs last year, and was chasing a surging issue for months before I found this thread. Ford saved a penny and didn't include a small clamp for this one so it's easy for it come loose.

Engine stuttering, slipping under WOT, no boost.

2014 Sport. Here's the problem. Under wide open throttle, Flooring the accelerator like when you pass another vehicle...or at least lets say 80% throttle or more. - Transmission drops a couple gears and the vehicle takes off, RMP's around 4k - All of a sudden the engine starts...

www.explorerforum.com

 

[Chickensandwich]

It’s got great boost, takes off like a rocket. Acceleration doesn’t seem affected. It’s more of the cruising speeds where this issue comes up. At low speeds (20-30) is where it’s affecting my shifting. Higher speeds, it’s just annoying.

 

[mguy13sport]

Is your torque converter locking and unlocking? Especially at low speed this would be noticable as RPMs will flare up and down with light throttle.

If your engine RPMs surge while in park/neutral then this would rule out the torque converter and would definitely be a vacuum/timing issue.