2013 Roush Raptor misfire at higher levels of boost

[MTF]

I would call JDM first.

What Temp thermostat are you running?
Was it doing this during the winter?
Only 93 Octane, YES?
When was the last time you added injector cleaning? And ethanol enzyme treatment?
Both should be added twice a year at minimum.
When was the last time you cleaned the MAF sensor?
I cleaned mine every 3 to 4 months when I lived in NYC.
And swap out the air filter every 3 to 4 months.

You can try pulling a 1 degree timing.

 

[UVBNAXED]

Always ran premium, never anything less. Stock thermostat. I use royal purple injector cleaner 2 times a year. I’ll go after the MAF and clean that. I service the air filter every 3,000 miles.

 

[MTF]

I know JDM likes to run the stock 195-degree thermostat, but I would at least try going to 180, it will help some when traveling at speed.
JDM doesn't lower the OEM radiator fans to jump on earlier, like the Whipple Tune on the Whipple SC kit does.
Or they may now, can't hurt to ask.
Do you know if you have the larger HE on the Roush kit?

I'm not a fan of Royal Purple, I use Techron concentrated Plus, works for me the past 12 years being SC'ed.

 

[downforce137]

the spark is getting blown out because the gap is too large.. knock it down to .028..

 

[UVBNAXED]

the spark is getting blown out because the gap is too large.. knock it down to .028..

I’ll try that next. I had taken the rear elbow off the SC to get the driver’s side valve cover off to inspect for broken valve springs. Plus side, valves are good.

 

[UVBNAXED]

I know JDM likes to run the stock 195-degree thermostat, but I would at least try going to 180, it will help some when traveling at speed.
JDM doesn't lower the OEM radiator fans to jump on earlier, like the Whipple Tune on the Whipple SC kit does.
Or they may now, can't hurt to ask.
Do you know if you have the larger HE on the Roush kit?

I'm not a fan of Royal Purple, I use Techron concentrated Plus, works for me the past 12 years being SC'ed.

I don’t believe I have the larger HE kit. I was looking at going with a larger one in the future.

 

[1BAD454SSv2]

I always followed if you go half throttle and and highest gear under load and it misses usually Ignition related . That stress's ignition the most . Full throttle miss is fuel related , not enough pressure on plugged injector , but could be ignition related as well . Sure you didn't crack a plug installing ?

 

[1BAD454SSv2]

I just changed spark plugs and now the engine is misfiring.​

It is common to have new misfire issues after changing plugs. This is commonly caused by installed damaged plugs or damaging the plugs during installation. Start by removing the plugs and closely inspecting them for cracks or issues. Confirm spark plug is correct and reinstall spark plugs that are found to not have any issues.

What if the misfires still happen after a new set of spark plugs?​

If the misfires continue after changing the plugs or are cylinder specific, the next test is to move the coil and boot from the cylinder that is having the issue to a cylinder that is not having an issue. Example: P0302 means cylinder 2 is misfiring. Remove the coil and boot from this cylinder and swap it with cylinder 1. It is also a good idea to re-check the spark plug on cylinder 2 verifying that the plug is still in good condition and not cracked or damaged.

What does it mean if the misfire moves to a different cylinder?​

If the misfire follows the coil, you have your answer and need to replace the coil and boots. You can decide to test just the boots as this is something Ford does and if that is determined to be the issue it will save you money. Boots are much cheaper than coils and boots. If the misfire did not follow the coil to cylinder 1, there is only 1 other variable left. Fuel…

What if I still have misfires after changing plugs, boots and coils?​

Fuel injector issues will cause a cylinder specific misfire.

 

[Gumby]

I would say. If you didn't have a miss before you did the plugs and you have one now. Then it is something you did. wrong gap, defective plug, bad boot. boot not seated, I am not saying you did something wrong. I am saying it is more than likely something you touched. not a broke spring or injector or all the other stuff you are chasing. Now... it's not impossible that it is one of them but not likely. Unless "new plugs" were 5000 miles ago. and now you got a miss. That is a little different.

I guess what I am trying to say is.... while you were changing the plugs I don't think you broke a spring or clogged an injector on start up.

 

[UVBNAXED]

Thank all of you for the info. Going to go for the .028 gap this week. I’ll update ASAP