MK7 Misfire issue higher rpms

[Mk7casey]

At lower rpm the window is bigger. e85 has lower stoich so you must inject more. as rpm climbs there is less time to inject. it wants to hit afr target but can’t because there isno more time to inject fuel needed. leans and misfires. look at my first post you can see where it leans. less e85 means less fuel needed to inject. pulsewidth lowers. injectors happy.

ah I see, would new injectors fix the issue?

 

[Diggs24]

di injectors are thousands and i dont think cobb can control them. mpi is what you want. but you aren’t losing any power now on e45. want more power get a bigger turbo and mpi.

 

[Ghost GTI]

di injectors are thousands and i dont think cobb can control them. mpi is what you want. but you aren’t losing any power now on e45. want more power get a bigger turbo and mpi.

I legit hope that if I ever have an issue with my car down the line, you're still around the forum to help me out

 

[2slowvw]

Also... i feel like your tuner should have been able to see this in the logs you send them and know whats up. Allthough Diggs no doubt has more logs than sneakytuned has saved up.

 

[JerseyDrew77]

Also... i feel like your tuner should have been able to see this in the logs you send them and know whats up. Allthough Diggs no doubt has more logs than sneakytuned has saved up.

Yes, this! Your tuner should have caught this, or at least know about it, and make the changes accordingly.

 

[8byt]

I know this is older, but have you figured out your problem? Does it look anything like this

I haven’t been able to figure this out, car starts misfiring at 6k rpms every time. Can’t find anything in the logs to suggest where to start.

here is the log: https://datazap.me/u/dj8byt/log-1610908039?log=0&data=5-8

list of mods:
Eqt vortex xl

Mishimoto charge pipes

Mishimoto fmic

Bosch 4bar put sensor

Maperformance catted downpipe

Invidia cat back

Injen closed box intake

Auto tech high pressure fuel pump

Precision race works low pressure 450 fuel pump

Cts turbo mpi

Dkm clutch

Aem water meth system

Apr coil packs

Cobb access port

Denso plugs

 

[Mk7casey]

I know this is older, but have you figured out your problem? Does it look anything like this

I haven’t been able to figure this out, car starts misfiring at 6k rpms every time. Can’t find anything in the logs to suggest where to start.

here is the log: https://datazap.me/u/dj8byt/log-1610908039?log=0&data=5-8

list of mods:
Eqt vortex xl

Mishimoto charge pipes

Mishimoto fmic

Bosch 4bar put sensor

Maperformance catted downpipe

Invidia cat back

Injen closed box intake

Auto tech high pressure fuel pump

Precision race works low pressure 450 fuel pump

Cts turbo mpi

Dkm clutch

Aem water meth system

Apr coil packs

Cobb access port

Denso plugs

that’s exactly what mine did, I was on full e85 when it happens, and I believe it has something to do with injectors because when I lower the ethanol content it will go to 7k with no issues. I recently sold the car so I never actually fixed it but was told if I went with MPI my issue would be solved.

 

[Diggs24]

How do the plugs look? Tried any other brands?

 

[Diggs24]

and do you have a nonmeth tune to try?

 

[8byt]

that’s exactly what mine did, I was on full e85 when it happens, and I believe it has something to do with injectors because when I lower the ethanol content it will go to 7k with no issues. I recently sold the car so I never actually fixed it but was told if I went with MPI my issue would be solved.

I have mpi, and we haven’t even started the ethanol tune because this keeps happening. I had the tomioka turbo and switched it out to the eqt and changed the fuel pump from a 305 to a 450. those are the only changes between my last tune to this one, and we can’t figure it out.

 

[8byt]

How do the plugs look? Tried any other brands?

They’re brand new to the turbo, I gapped them at .24 I don’t have a non wmi tune for this turbo I do for the old one but we were running high boost pressure and don’t want to blow my engine just yet.

 

[Diggs24]

I would try a different plug first. If that doesn't work move off the meth (yes you'll have to retune). Try the Rutheniums. Gap to 0.022"

 

[Diggs24]

I also wonder why pressure is rising at the MPI rail while duty is falling.

https://datazap.me/u/dj8byt/log-1610908039?log=0&data=8-24-25

It makes sense it will lower duty to hit fuel pressure setpoint but I wonder why pressure is rising. I wonder if some cavitation isn't going on.

 

[8byt]

Hmm you think there’s air getting in the fuel line for the secondary rail?

 

[JerseyDrew77]

First start with switching out your plugs to a different brand, like the ones that Diggs suggested or if those don't work, then maybe some NGK racing plugs.