Misfire on all cylinders, but mostly on #1

[dingurt1]

[UPDATE] Misfire on all cylinders, but mostly on #1

So prior to my downpipe and stage 2 APR tune, I didn't have any issues with misfiring. Once the S2 was done, if I slowly roll into the throttle and build a bit of boost, the car violently loses power for a second and keeps on like normal... feels like someone taps the brakes. Sometimes it does it a few times on a partial throttle pull, and sometimes it does it on a WOT pull.

Any ideas?

 

[RedHotVAG]

So prior to my downpipe and stage 2 APR tune, I didn't have any issues with misfiring. Once the S2 was done, if I slowly roll into the throttle and build a bit of boost, the car violently loses power for a second and keeps on like normal... feels like someone taps the brakes. Sometimes it does it a few times on a partial throttle pull, and sometimes it does it on a WOT pull.

Any ideas?

I just found this, wondering if this could be why. If so, you're just not gonna be able to get them to fix it under warranty as the problem would not present itself once you go back to stock. You can try get a JB Stage 1 and get Map 6 when it comes out end of this month and you can adjust boost by RPM. Or try and free up your exhaust flow more if you just have a downpipe like me, maybe go full exhaust.

 

[Tucker3381]

Totoro, that was for the mk6's.

 

[PRND[S]]

OP, have you spoken to the tuner who installed the downpipe and flashed your car? I wonder if they flashed you with the wrong file.

 

[RjRacing]

What fuel are you running? You may want to have your coils checked as well.

 

[dingurt1]

PRND, I installed the downpipe myself and my local VW dealer did the tune. I'm pretty confident they installed the correct tune.

RjRacing, 93.

The car is with them now so they can do more diagnostics. The only thing that I'm not sure about is when it does the bucking, the wastegate or diverter valve is fluttering like crazy. I know it's supposed to flutter some, but this thing sounds pissed. When I installed the APR intake, I could hear it a lot more than stock, but it was only S1 at that point.

 

[Baldilocks73]

My friends did that on the UM tune. They had to make some adjustments and reflash. The downpipe was causing problems.

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[dingurt1]

My friends did that on the UM tune. They had to make some adjustments and reflash. The downpipe was causing problems.

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Adjustments in the tune?

 

[Baldilocks73]

Adjustments in the tune?

Yes. They had to change some of the parameters because of the free flowing down pipe. He was getting surges and shudders under hard acceleration.

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[dingurt1]

UPDATE: got the car back from the dealer, and it turned out to be a broken spark plug.

 

[gn4rwhals]

That's very strange, maybe the plug was just burnt out and half working?

 

[SamG]

Has there been any further updates? What caused the spark plug failure?

A guy in SA had the same issue, dealer fixed the plug. Car started missing again and caused piston damage. Apparently an issue with fueling/running lean.

 

[skian]

Has there been any further updates? What caused the spark plug failure?

A guy in SA had the same issue, dealer fixed the plug. Car started missing again and caused piston damage. Apparently an issue with fueling/running lean.

What tune was this with?

 

[SamG]

What tune was this with?

APR stage 2

 

[gn4rwhals]

I wonder if the car had a knock event and the piston smacked the spark plug just right.