Misfire at High RPM

[Lucas Higdon]

I had a random misfire on stock hpfp internals, so I figured I needed better fuel flow, upgraded that everything is fine with it, still having the high RPM random misfire and it only misfires when Im done accelerating(slowing down) , Im going to change the spark plugs and clean the vaccum lines but didn't know if anyone had a answer to what could be causing this misfire.


Should also mention that this code only appears at high rpm. ive cleared it and daily drove it for a week no hard acceleration, just normal driving, but the moment I go above 5k RPM is when it will throw the misfire code

 

[L337TurboZ]

Check plug quality and plug gap. Set to 0.026-0.028

 

[Easter Bunny]

Stretch the springs inside your plug boots while you have them off

 

[Lucas Higdon]

Stretch the springs inside your plug boots while you have them off

What does this exactly mean? Im still new to working on this car

 

[Easter Bunny]

When you take the coils off turn them over there is a spring I side the boot which connects the coil to the plug give it a little tug to stretch it out and make sure it is making solid contact with the plug

 

[Lucas Higdon]

When you take the coils off turn them over there is a spring I side the boot which connects the coil to the plug give it a little tug to stretch it out and make sure it is making solid contact with the plug

just finished doing this, founds some videos on youtube of it, super easy, also should mention I discovered my bypass valve had no gasket, would that cause issues?

 

[Raider]

just finished doing this, founds some videos on youtube of it, super easy, also should mention I discovered my bypass valve had no gasket, would that cause issues?

A boost leak at minimum. Plugs are a start. Injector seals next.

 

[Easter Bunny]

just finished doing this, founds some videos on youtube of it, super easy, also should mention I discovered my bypass valve had no gasket, would that cause issues?

Probably

 

[Lucas Higdon]

A boost leak at minimum. Plugs are a start. Injector seals next.

A boost leak at minimum. Plugs are a start. Injector seals next.

I will keep this in mind, I don't think its gonna be a seal problem tbh Im not having rough idle or hard starts or low rpm misfires, just very high rpm misfires unless im just wrong on the research ive done about our injector seals