GEN 2 Cylinder 2 misfire…swapped coils and didn’t move

[91Eunos]

Will run a compression test tomorrow when I can find my stuff after moving crap between garages, but in the meantime did the basics: swapped coils (twice), and still getting misfire on the same cylinder. Swapped plugs too, and misfire still on cylinder #2.

Have a new set of plugs, and will swap them too just because I’m in there, but honestly, the ones in there now have <15K miles on ‘em and look perfect; very light brown ash and no moisture/signs of oil leakage at all.

I guess it could be an injector or a loose/worn wire, and will run that to ground (heh, see what I did there?) if possible, but man, I hate chasing electrical gremlins if that’s what it is.

Edit: truck has 103K miles, has had cam phasers done (x3 LoL), and all major service performed by dealer. Zero issues other than cam phasers and IWE. Had one coil going out a couple years ago, but swapped out and replaced with a factory replacement.

Edit #2: only seems to happen when I’m at full throttle. If I ease it up to 80+ mph, there’s no issue at all; runs smooth. If I apply full throttle, the check engine light starts flashing, and the whole truck shakes…you can see the hood shaking like crazy! It goes away after a few seconds, and the check engine light usually extinguishes too. Same code every time: P0302

Any ideas from the hive mind?

@FordTechOne any input appreciated.

 

[FordTechOne]

Will run a compression test tomorrow when I can find my stuff after moving crap between garages, but in the meantime did the basics: swapped coils (twice), and still getting misfire on the same cylinder. Swapped plugs too, and misfire still on cylinder #2.

Have a new set of plugs, and will swap them too just because I’m in there, but honestly, the ones in there now have <15K miles on ‘em and look perfect; very light brown ash and no moisture/signs of oil leakage at all.

I guess it could be an injector or a loose/worn wire, and will run that to ground (heh, see what I did there?) if possible, but man, I hate chasing electrical gremlins if that’s what it is.

Edit: truck has 103K miles, has had cam phasers done (x3 LoL), and all major service performed by dealer. Zero issues other than cam phasers and IWE. Had one coil going out a couple years ago, but swapped out and replaced with a factory replacement.

Edit #2: only seems to happen when I’m at full throttle. If I ease it up to 80+ mph, there’s no issue at all; runs smooth. If I apply full throttle, the check engine light starts flashing, and the whole truck shakes…you can see the hood shaking like crazy! It goes away after a few seconds, and the check engine light usually extinguishes too. Same code every time: P0302

Any ideas from the hive mind?

@FordTechOne any input appreciated.

Before getting too deep into it you’ll want to use a scan tool to monitor the fuel system PIDs. If the misfire occurs when the PCM switches from PFI to DI, you can be pretty sure the direct injector for that cylinder is at fault.

 

[91Eunos]

Thank you @FordTechOne appreciate your time and input!

At 100K miles, it’s probably time to get those injectors tested and rebuilt/replaced anyway.

 

[Hadlebfc]

My 2019 truck is at 40k miles and cylinder 3 is consistently going between P0303 P2306 or P0353. New plug, new coil and still doing that. Rechecked plug, coil, and wire connection and they look fine. It’s only happening once I Rev it hard too. Thoughts??

 

[FordTechOne]

My 2019 truck is at 40k miles and cylinder 3 is consistently going between P0303 P2306 or P0353. New plug, new coil and still doing that. Rechecked plug, coil, and wire connection and they look fine. It’s only happening once I Rev it hard too. Thoughts??

You have DTCs for the primary side of the ignition; P0353 is Ignition Coil 'C' Primary Control Circuit/Open and P2306 is Ignition Coil 'C' Primary Control Circuit Low. These need to be diagnosed first; P0303 is just a conditional DTC from ignition issue.

 

[smurfslayer]

Thank you @FordTechOne appreciate your time and input!

At 100K miles, it’s probably time to get those injectors tested and rebuilt/replaced anyway.

So... what was the outcome?

 

[91Eunos]

So... what was the outcome?

It was the coil…easy fix. I initially swapped the wrong coil, because I’m a ******* and mis-remembered the firing order on the 3.5 ecoboost. LoL.

 

[smurfslayer]

Glad you’re back in business!