Intermittent misfire 2019 Ford F-150 2.7 Ecoboost S-Crew 4x4

[meep]

I had exact same issues 3.5ecoboost, changed the gapped plugs still misfire under load, called ford to order all new coils and when they told me a price for them I was Ok, that is expensive I will just scan to see which one is the faulty one.
And then parts guy says to me, did you ever change the boot on the coils because those are serviceable items, I said no i didn't but I will.

Got the boots, in Canada $15 a piece, swapped them and freaking voila no missfires anymore. Total milage on the tunned truck 270k km form which about 260k km on different tunes . Still on the original coils .

When I looked on those rubber grommets with little spring inside I would never freaking guess that they would solve my problem

Huh. I wish I’d known that. I ordered the boots from RA when I did my plugs and their OEM boots did not fit, so I reused the old ones. New coils came a year later after misfires, and I was chasing ghosts and finally tightened the plug gap until I sold it.

They really don’t need rubber boots except for rear passenger plug, which is blocked by a metal coolant line on the 2.7. You have to have a rubber boot to clear all that. Just a little more engineering thought and they could have used a solid coil which reached all the way down.

I really wish I’d known that…

 

[1911CHAMPION]

I have yet to take the truck in to Ford to have the PCM programming done for the 24E12 recall. Is there a possibility that that has anything to do with the intermittent misfire that I am having?

I ragged on it on some back country roads again yesterday driving home from work and could feel a lot of misfiring but when I got home and checked for codes, there weren’t any. Do misfires caused by a weak coil or one that is no longer capable of producing a spark under higher load and boost pressure produce a pending misfire code in the system?

Has anyone had the 24E12 recall PCM reprogramming done on their own vehicle and if so did you notice anything different about vehicle performance, mpg, or behavior after it was completed?

 

[snowshew]

I have yet to take the truck in to Ford to have the PCM programming done for the 24E12 recall. Is there a possibility that that has anything to do with the intermittent misfire that I am having?

I ragged on it on some back country roads again yesterday driving home from work and could feel a lot of misfiring but when I got home and checked for codes, there weren’t any. Do misfires caused by a weak coil or one that is no longer capable of producing a spark under higher load and boost pressure produce a pending misfire code in the system?

Has anyone had the 24E12 recall PCM reprogramming done on their own vehicle and if so did you notice anything different about vehicle performance, mpg, or behavior after it was completed?

I had it done. No changes noted. I have been following your thread with interest. I had misfires in multiple cylinders and frequently in cylinder 6. It manifested as a bit of a sputter or less-than-smooth idle which I did mention the dealer during transmission service some time back. Recently had a separate issue addressed and they found the codes and alerted me. I changed to the newer SP594 plugs and it is now smooth. As an aside, there was oil on the threads of plug 6 and I am suspecting this led to the more frequent misfires in that cylinder, perhaps exasperating whatever problem was caused by the factory plugs. I check for return of codes periodically and have found none. I will pull plug 6 after a while and look for oil again too, perhaps a bad spark plug tube seal, but it is apparently not covered by warranty. I have less than 20k miles on my 2020. Sending an oil sample in today also; curious about effects of long term misfires. Sure wish there would have been a CEL, I obviously wouldn’t have accepted “that’s just how it idles.”

 

[1911CHAMPION]

I had it done. No changes noted. I have been following your thread with interest. I had misfires in multiple cylinders and frequently in cylinder 6. It manifested as a bit of a sputter or less-than-smooth idle which I did mention the dealer during transmission service some time back. Recently had a separate issue addressed and they found the codes and alerted me. I changed to the newer SP594 plugs and it is now smooth. As an aside, there was oil on the threads of plug 6 and I am suspecting this led to the more frequent misfires in that cylinder, perhaps exasperating whatever problem was caused by the factory plugs. I check for return of codes periodically and have found none. I will pull plug 6 after a while and look for oil again too, perhaps a bad spark plug tube seal, but it is apparently not covered by warranty. I have less than 20k miles on my 2020. Sending an oil sample in today also; curious about effects of long term misfires. Sure wish there would have been a CEL, I obviously wouldn’t have accepted “that’s just how it idles.”

My idle and low load engine operation is completely smooth. The misfire(s) don’t manifest until WOT runs in 5th gear or higher above about 3,000 rpm. And this issue was not present before mid March of this year. Under low engine load and cruising on the highway it runs smoothly without issue.

I replaced the factory plugs with the SP594 units approximately 13,000 miles ago. I left the plug gaps as they were out of the box when I installed them. They were all dead nuts in the middle of the plug gap range. (Checked with a feeler gauge)

I cleared the misfire codes a few days ago hoping it would record another one but it hasn’t. To see if it’s the same cylinder(s) that were recorded before on 3, 4, & 6

 

[SubieRubyRoo]

My idle and low load engine operation is completely smooth. The misfire(s) don’t manifest until WOT runs in 5th gear or higher above about 3,000 rpm. And this issue was not present before mid March of this year. Under low engine load and cruising on the highway it runs smoothly without issue.

I replaced the factory plugs with the SP594 units approximately 13,000 miles ago. I left the plug gaps as they were out of the box when I installed them. They were all dead nuts in the middle of the plug gap range. (Checked with a feeler gauge)

I cleared the misfire codes a few days ago hoping it would record another one but it hasn’t. To see if it’s the same cylinder(s) that were recorded before on 3, 4, & 6

Based on what you’re saying and the logs you pulled, I’d figure out how to understand where your HPFP is supposed to operate. Idle & low speed is PI that’s off your intank pump. 3k in the boost will definitely have a good demand on your HPFP.

 

[meep]

My idle and low load engine operation is completely smooth. The misfire(s) don’t manifest until WOT runs in 5th gear or higher above about 3,000 rpm. And this issue was not present before mid March of this year. Under low engine load and cruising on the highway it runs smoothly without issue.

I replaced the factory plugs with the SP594 units approximately 13,000 miles ago. I left the plug gaps as they were out of the box when I installed them. They were all dead nuts in the middle of the plug gap range. (Checked with a feeler gauge)

I cleared the misfire codes a few days ago hoping it would record another one but it hasn’t. To see if it’s the same cylinder(s) that were recorded before on 3, 4, & 6

It starts ABOVE 3k rpm, not below? That is backwards from how a typical plug/coil failure occurs, unless boost pressure changes the general pattern.

What octane gas are you running?? Whatever it is, try changing it and see how it affects?? Hotspots? Overheating valves? Running too lean?? Isnt there a TSB out there now for an ECU flash protecting the catalysts by richening the fuel mix some??

 

[1911CHAMPION]

I’ve ran regular 87 octane from CostCo about 80% of the time except for road trips, then whatever is available.

I did try a full tank of premium and it didn’t seem to make any difference. The stuttering and jerking comes on just shy of 3,000 rpm at WOT in 5th gear or higher gears. Is that the magical crossover point for PI to DI injection circuits?

Not all cylinders are producing the misfire though which makes me wonder if it actually is a fuel issue or not.

Not TSB, it’s an active recall. 24E12 and I have yet to have it performed on my truck.

 

[meep]

unfortunately it’s not that simple … there is not a specific rpm where the two FI systems changeover. They gradually overlap each other.

 

[wtd]

There should be data PIDS for actual and desired fuel pressures for both the low-pressure side and high-pressure side. I would see if you can find them and then drive the truck under the conditions that the misfire occurs to see if they match. I would also find out what the theory and operation is for the fuel system, so you know when the low-pressure side is used vs the high-pressure side.
As far as the ignition side of things, rarely do multiple coils fail at once but I guess it could happen.

 

[1911CHAMPION]

Well, I found the problem. I pulled the number four and number six spark plugs out this evening and they have arcing literally engraved into the porcelain along the side of the plug. They aren’t cracked or anything, so I’m wondering what caused this to start happening on 3 different plugs... So, the spark was grounding out on the spark plug tube; that was causing the misfire(s).

So I intend to order new boots from RA but now the question is, do I replace these with another set of Motorcraft SP594 or do I buy the NGK 95927 ILTR6S8 Laser Iridium’s? Either way, I think I’m going to change these out in about 30,000 more miles and I believe either of these should easily be able to go that far. Truck is stock and I do not intend to put a tuner on it.

The coil boot number I believe is Motorcraft WR6152 (alt # FU7Z12A402A).

 

[YZJB]

there you go! Interesting. I would go with the NGKs as they’re a little cheaper. Good work finding the cause of the problem

 

[snowshew]

What was the condition of the boot? Were there contaminants in it? What is responsible for arcing like this?

 

[1911CHAMPION]

The boots look fine, but I’m going to wipe them out and then load them up with a new layer of dielectric grease before putting them back in. Or should I put the boots back on dry?

 

[meep]

From what I read, the fomoco plugs are manufactured by NGK. I think either would be fine. I also learned that the fomoco plugs are a very high end NGK with precious metals on both tips. The NGK parts line gets a little confusing. I would NOT reuse the rubber boots. I recent post somewhere around here gave evidence that these boots fail, which may explain why 2 of my cylinders were seeing misfires even though the plugs and coils were new.

Do NOT buy the boots through rock auto. The supposedly OEM boots they sold me did not fit the oem coils. Buy the boots from ford.

 

[panthermike]

The boots look fine, but I’m going to wipe them out and then load them up with a new layer of dielectric grease before putting them back in. Or should I put the boots back on dry?

I would think that you would want the grease. Also be careful not to go too thick as that can cause issues to.

Good detective work! hopefully it won't give you any issues for a long time.