1.4 TSI CAXA 122hp Scirocco 2010 - Wavy acceleration and a rough, shaky idle

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Sun 24 Sep 2023 21:18
1.4 TSI CAXA 122hp Scirocco 2010 - Wavy acceleration and a rough, shaky idle - ChrisSC

Hi everyone,

I've trying to track down this issue im having with a rough idle and wavy acceleration above 2.5k RPM. (1.4 TSI CAXA 2010 Scirocco 122hp)

I used to have misfires on idle/boost but I solved this by replacing plugs and adjusting gap to .75mm and replacing OEM coils with R8 coils.

The engine has 0 hesitation and even more power when I unplug the Boost pressure sensor and idles smooth so I thought the sensor is faulty.

I bought a new one, reset the ECU and started the car, it idled smooth for a few minutes then went back to its old ways, as if the ECU relearned something based off the data it got from the new sensor.

Engine idles at 640 RPM (Is that normal?) and fuel pressure seems normal at 50.26 bar.

Charting boost pressure on full boost i can see the boost pressure going in waves in sync with what i can hear from the car.

Car throws 0 codes and even a VW dealership couldn't figure out whats wrong.

What ive done so far:

  • Timing chain is recently replaced
  • Replaced sparkplugs with tighter gap
  • Replaced OEM coils with R8 coils
  • Replaced Coil connectors
  • Replaced boost pressure sensor
  • Intake valves have been walnut blasted so no carbon build up anymore

Any ideas how i can further diagnose this?

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Sun 24 Sep 2023 22:30
1.4 TSI CAXA 122hp Scirocco 2010 - Wavy acceleration and a rough, shaky idle - elekie&a/c doctor
Lots of air intake and boost pipes on these . Have you smoke tested the air intake system for any leaks .,?
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