4,000 rpm misfire

[Flamennn]

I haven't gotten to the bottom of this problem. my car seems to misfire around 4,000 rpm even if i hold the gas pedal down. here is a video of what its doing.

DSM problem HELP!! - YouTube

I have replaced the wires, computer, and cleaned the EGR. i have not put the other coil pack on yet.
Please help!

 

[TSi Kid]

It may just be the network i'm on but I can't view the video..

 

[Flamennn]

The engine misfires around 4,000 rpm. if i hold the gas pedal down it misses alot around 4,000 rpm.

 

[TSi Kid]

Almost asked if you did a boost leak test before I saw you were NT lulz.

What happens if you ease into higher rpms and not do WOT pulls?

 

[Chrispy0530]

When your reaching 4k RPM, are you implying WOT pulls? Or normal acceleration? I'd check your spark plug gaps and go from there.

 

[95TalonOwner]

With the CEL shutting off with misfire, that leads me to believe that there may be a harness short somewhere. Have you checked all the wiring? 4000rpm could be the sweet spot with vibration causing a short. Common place to look would be by the cam sensor where the harness is bolted to the head. It likes to rub through a lot in that place.

 

[Flamennn]

No i slowly pressed on the gas pedal to get it up the 4,000 rpm's then i put the petal to the floor.

I cant get into the higher rpm's it just misfires there at 4,000 rpm's

The harness is all plugged in, i believe i checked everything with the wiring harness.

 

[6A12TT-7G]

Looks like limp-mode...

My first thought is that your EGO sensor is faulty, from the looks the ecu is getting nothing from it and is shutting down to protect the engine from lean-out. I'd recommend researching the sensors used on your engine and testing each with the correct methods, most involve a multimeter. Confirm that all your sensors and switching mechanisms operate within their limits before searching for shorts.

The CEL will stay lit in limp mode and the ecu will limit the engine's ability to rev.

 

[notched]

I had the same problem with my 5.0. I had a wire break that went to the maf harness. No matter if I went WOT or just slowly pushed the pedal. Would bang off 4200.

 

[95TalonOwner]

By the looks of the tach and CEL twitching/flashing, the ecu is definitely shorting out somehow. My money is 100% still on a short somewhere.