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EPC Light at high RPM, EQT tune second revision *Update: Car is now a hot mess

PerceivedShift

Autocross Champion
Location
Virginia
Any update. I put in new NGK racing plugs, new injector and im getting an epc at 6600ish rpm. No clue what it is.
Still had some misfire issues high up on the ER10s, ER10s just don't last, switched to densos from FCPeuro. Seems to run better on densos, no EPCs yet, though there is still evidence of misfiring. More than likely I need to replace my PCV and coils, both have 83k miles on them.

Here are some recent pulls from last month at Dominion raceways street racing night, all pulls done from a roll:

https://datazap.me/u/perceivedshift/sep-9-dominion-raceway-runs-5-7

https://datazap.me/u/perceivedshift/sep-9-dominion-raceway-runs-2-3
 

Superfreak

Autocross Champion
Location
Denver
Car(s)
‘19 M2C, ‘05 Taco
Still had some misfire issues high up on the ER10s, ER10s just don't last, switched to densos from FCPeuro. Seems to run better on densos, no EPCs yet, though there is still evidence of misfiring. More than likely I need to replace my PCV and coils, both have 83k miles on them.

Here are some recent pulls from last month at Dominion raceways street racing night, all pulls done from a roll:

https://datazap.me/u/perceivedshift/sep-9-dominion-raceway-runs-5-7

https://datazap.me/u/perceivedshift/sep-9-dominion-raceway-runs-2-3
fwiw, I don’t know a lot about tunes or tuning, but I have learned about hpfp in the past few months and I’m fairly certain that you shouldn’t be @100% hpfp effective pump volume.
 

PerceivedShift

Autocross Champion
Location
Virginia
It's so strange to me how many issues seem to be pinned on plugs/coils.. just seems like an easy out. You can try every plug under the sun, but if you're at 100% duty cycle at low(ish) RPM, the HPFP is struggling.

I don't know how that can be pointed at plugs.. but I'm not a tuner, so 🤷🏼‍♂️
I went over this with EQT a while ago, pointed this concern out specifically after going back and forth on here, they told me fuel rail pressure looks good and to stop listening to random people on the forums. 😅
fwiw, I don’t know a lot about tunes or tuning, but I have learned about hpfp in the past few months and I’m fairly certain that you shouldn’t be @100% hpfp effective pump volume.
Fuel pressure remains around 3300psi, also see answer above.
 

Superfreak

Autocross Champion
Location
Denver
Car(s)
‘19 M2C, ‘05 Taco
I went over this with EQT a while ago, pointed this concern out specifically after going back and forth on here, they told me fuel rail pressure looks good and to stop listening to random people on the forums. 😅

Fuel pressure remains around 3300psi, also see answer above.
I went back and checked my emails to/ from EQT and I believe that you’re correct, that it can run at 100% but you have to watch for when rail pressure drops off.
 

mrmatto

Autocross Champion
Location
Jacksonville, FL
Car(s)
2024 GTI DSG
1664971897773.png
 

PerceivedShift

Autocross Champion
Location
Virginia
3rd gear pull last night merging onto 64

Graphed both Speed (orange) and RPM (Blue) in excel to get a closer look at the relationship. The blips up in RPM are probably just bumps in the road, what im interested in are the dips in RPM, sometimes followed by a dip in speed as well. Starting at 10.7s you can see what looks to be some RPM fluctuations which could be evidence of misfire, I thought I could feel a dip in power around that time as well.

Screenshot 2022-10-05 100906.jpg
 

Daks

Autocross Champion
Location
Toronto
Car(s)
GTI PP
3rd gear pull last night merging onto 64

Graphed both Speed (orange) and RPM (Blue) in excel to get a closer look at the relationship. The blips up in RPM are probably just bumps in the road, what im interested in are the dips in RPM, sometimes followed by a dip in speed as well. Starting at 10.7s you can see what looks to be some RPM fluctuations which could be evidence of misfire, I thought I could feel a dip in power around that time as well.

View attachment 262289
We could be dealing with the same issue, go to my build thread.
 

CaptainRatty

Autocross Champion
Location
Winston-Salem, NC
Car(s)
MK7 GTI
I went back and checked my emails to/ from EQT and I believe that you’re correct, that it can run at 100% but you have to watch for when rail pressure drops off.
EQT told me that my fuel pressure drops were normal. I should have gone with my gut and addressed it as soon as I noticed it.
 

Acadia18

Autocross Champion
Location
Here the entire time
Car(s)
2019 Golf R
ngl, all this shit just reaffirms I made the right choice to bail on a hybrid. I could never deal with this shit.
 

GTIfan99

Autocross Champion
Location
FL
ngl, all this shit just reaffirms I made the right choice to bail on a hybrid. I could never deal with this shit.
Going DTR instead?
 

Acadia18

Autocross Champion
Location
Here the entire time
Car(s)
2019 Golf R

GTIfan99

Autocross Champion
Location
FL

Daks

Autocross Champion
Location
Toronto
Car(s)
GTI PP
ngl, all this shit just reaffirms I made the right choice to bail on a hybrid. I could never deal with this shit.
0 regrets from me. I get this misfire when I'm like 300 RPM before the absolute redline, I can just shift at 6500 and have no issues. It was worth it. The car is an absolute blast to drive.
 
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