Surge under WOT. No check engine light.

[Dirtleg]

First post here in a really long time. On to the issue.

Getting a surge under full throttle conditions. No other time.

Some details.
Car 2015 Ecoboost 6 sp manual PP built 12/2014. So yes a Spain engine.

Mods are.
ATM intercooler.
3 inch catless downpipe.
Mishimoto catch can installed at 1K miles
Plugs changed out at about 40K.
Livernois tune since 18K miles.
85K miles currently on the car.
Always running 93 octane from a veritable laundry list of gas stations. Basically I fill up whenever it's convenient. Different fuels have made no issue. (And why would they? They all come out of the same pipe 15 miles from my house)

So for example if I go to pass on a 2 lane road, 3rd gear WOT it pulls hard till about 4.5-5k and then I get what definitely feels like a misfire/surge. Never have I gotten a misfire code or check engine light of any kind. Not hearing detonation either.

In normal driving everything is fine. Smooth and predictable. Mileage is good and consistent with what I've always gotten.

Wondering if my HPFP is possibly not flowing like it used to. Makes a slight ticking noise but it's always done that from new.

Also wondering about the throttle body. Possibly fluttering under WOT.

So what are others thoughts? Anyone else had an issue like this? What was the solution?

I have not switched back to the stock tune. It's been tuned for 3 1/2 years. Just started this recently. Doubt it's a tune issue.

Thanks.

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[BoostedMTBer]

does it feel like it is switching between stutter/surge 3-4X a second in the upper RPM range? I had the same issue after installing my DP and working on my tune with Ryan a month ago. He called it an ignition advance issue. He recommended checking my AP software to make sure it was up to date- which it was.
from there I pulled my plugs, and my gaps had widened on me.
New plugs would be my recommendation. I swapped in some new NGK's and it fixed it for me. Unfortunately less than 100 miles later I spun a rod bearing and my engine is now in pieces in my garage. Don't want to freak you out, but I can't help but to think that the stress from the high RPM surging had something to do with it =\

 

[Dirtleg]

Your description isn't far from my impression of what it's doing. I will check my plugs.

With my stock plugs I'd get a misfire code and check engine light but it never felt like it was surging.

Could be the replacement NGK's I put in are just worn now.

Be nice to get the top 1500 rpm's back to being safe to use.

 

[brl0301]

why not do a couple data logs and sent them to livernois? Im sure whatever is happening would be visiable in a log and hopefully easily fixed

 

[Dirtleg]

why not do a couple data logs and sent them to livernois? Im sure whatever is happening would be visiable in a log and hopefully easily fixed

That's a good idea. Wonder if I can get a good enough data log using torque. Sadly the Livernois tuner doesn't have data-logging capability. At least the old one I have does not. It appears they have a newer unit that does now.

 

[Dave9878]

Hey, I have a 2018 5.0 GT, and the surging your talking about is happening to me also. Tip in and itll go to redline and stutter and jolt the car before resuming throttle. I read it could be an ignition timing issue. I have a brand new motor after spinning a bearing. I was having occadional surging before my new motor, and this one with 1.3k miles is doing it. I hope its ignition related.

 

[Chef jpd]

If put my money on the plugs.
The gaps open up in as little as 10k miles.

 

[KewlWinter]

Plugs would be my first thing to check. Also, check the coils and make sure they all fall within test ranges. On the 2015 I owned previously, I had a similar issue and after chasing it for a while found that 1 of the coils, while not failed completely, was intermittent at high rpm. Replaced with the MSD coils at the time since they were much cheaper than the OEM and the problem went away.

 

[BoostedMTBer]

All solid advice. Always involve your tuner and if it's not the plugs, id take a look at the coil packs as KewlWinter mentioned.
any update? Did you pull the plugs and check the gaps?

 

[Dirtleg]

All solid advice. Always involve your tuner and if it's not the plugs, id take a look at the coil packs as KewlWinter mentioned.
any update? Did you pull the plugs and check the gaps?

No this past weekend I was in Charlottesville Saturday and worked on my 93' F350 interior Sunday.
Started working from home back in October so don't need to drive much these days. I'll get to it soon I expect.

Thanks again for all the replies.

 

[DUNDEM]

If put my money on the plugs.
The gaps open up in as little as 10k miles.

i think you Nailed it. 45k on the same plugs is not what theses cars like.

OP how often do you change the oil? NOT that it has anything to do with the issue.

 

[macdaddyslomo]

I had the exact same issue, while i was datalogging for Ryan from PD.

It turned out to be plugs. I had purchased pregapped plugs from tune+.

When I pulled the plugs to check gap, all four were at .034.

I replaced with new iridium NGK's and gapped myself to .028 and this fixed the issue completely.

 

[Dirtleg]

Okay so just an update. Found the problem and it's embarrassing. I didn't drain my catch can at the regular interval and thought I had. When I opened it up it was way more full then it's ever been.

Once that was sorted problem went away completely. Guess it was ingesting small amounts of catch can residue under WOT. A little scary actually but fortunately no harm came from it.

So operator error.

My iridium NGK's which I had gapped at .28 were all still hovering around .28. So no plug issues anyway.

 

[Hellman109]

To be fair, without a catch can you would have been putting that in the intake the whole time. Id bet it was more because you were blocking that port and causing issues then the oil going anywhere.

Glad its sorted for you though.

Note to self: go check my catch can

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