Misfiring help

[Klewee8]

I’ve been a member for a long time now. Just never have posted.

I have a 2014 roush with 106k miles. This is the second motor in this truck replaced by ford roughly 12k miles ago.

Recently I have been getting misfires at high RPM’s. Getting a cylinder 4 misfire code with blinking check engine light that doesn’t stay on. Spark plugs are brand new, coils new, and I don’t believe it’s fuel related, pump was checked, Fuel pump driver module was also just replaced. Only thing now is I’m thinking 02 sensors? I have a cat delete and use non-foulers to not get the truck to throw codes. Before, I had the truck tuned to have the rear 02 codes shut off but then I blew the motor and went back to original roush tune.

Besides the misfire truck runs fine. Doesn’t misfire unless I’m heavy on the pedal and high RPMs.

Any thoughts? I just want to see what else I’m missing before I end up throwing annoying cats back on.

(Picture isn’t related I just got a nice pic with the doggo while flying drones for work)

 

[Gumby]

I’ve been a member for a long time now. Just never have posted.

I have a 2014 roush with 106k miles. This is the second motor in this truck replaced by ford roughly 12k miles ago.

Recently I have been getting misfires at high RPM’s. Getting a cylinder 4 misfire code with blinking check engine light that doesn’t stay on. Spark plugs are brand new, coils new, and I don’t believe it’s fuel related, pump was checked, Fuel pump driver module was also just replaced. Only thing now is I’m thinking 02 sensors? I have a cat delete and use non-foulers to not get the truck to throw codes. Before, I had the truck tuned to have the rear 02 codes shut off but then I blew the motor and went back to original roush tune.

Besides the misfire truck runs fine. Doesn’t misfire unless I’m heavy on the pedal and high RPMs.

Any thoughts? I just want to see what else I’m missing before I end up throwing annoying cats back on.

(Picture isn’t related I just got a nice pic with the doggo while flying drones for work)

I would pull the plug on that cylinder. Get a look at it. Just because it is "NEW" doesn't mean squat. It could be gaped wrong. For super charger I think they (JDM) recommend a different gap Actually I think they recommend a colder plug all together, than the naturally aspirated. The "NEW" plug could have, cracked purslane, too much resistance, Etc ,Etc....... My point is "NEW" does it mean good. I would start there, swap coil packs next. see if the miss moves with the coil pack. Also spray the bottom of the Coll where the boot meets the head with water. If you get arcing the boot might be bad. You may have to brake torque the engine. witch will require someone you trust not to run you over. LOL since you get the "MISS" under Load.
I want to say the plug should be .028 Gap. I cant remember the the number I am sure someone here will or you can search it if you need it faster.

 

[MurderedOutSVT]

Definately a colder plug fpr FI motors. Could be burnt/fouled out. Start there

 

[IvanDragunov]

I had misfire on cylinder 2. I changed all the spark plugs, all the coils and the injector of the cylinder concerned. No change. In the end it was the rocker arms totally destroyed, we don't know how it happened but the rollers were completely shot.
Replaced all the rocker arms and the engine purred properly again.

 

[Klewee8]

I had misfire on cylinder 2. I changed all the spark plugs, all the coils and the injector of the cylinder concerned. No change. In the end it was the rocker arms totally destroyed, we don't know how it happened but the rollers were completely shot.
Replaced all the rocker arms and the engine purred properly again.

Did you end up replacing the rockers yourself? Or did you have a shop/ford do it? Also did you hear any knocking or anything when your rocker arms went bad? Because I’m not hearing anything and have no sign of anything else going wrong. Just the misfiring. If you had a shop/ford do it what was the cost?