N55 Throttle Fluctuating - Any advice? Log Included

[The Sasquatch]

Hi Guys,

New to the site, but keen for some well informed opinions!

Car: E90 335i, N55, Manual

1) When accelerating the car doesn't pull cleanly/consistently, there is some easing and re-surging when accelerating. This actually happens most noticeably under light acceleration.

2) Idle also has a bit of vibration/tends to be sometimes a hundred revs or so lower than 650 per minute.

3) Throttle response is a little sluggish

The log below shows that the throttle position is fluctuating all over the place when the throttle pedal is constant. Any ideas as to what is the issue?

https://datazap.me/u/sasquatch/issu...on-wastegate-boost?log=0&data=2-4-15-17-18-20

Car has new:
Coils
Plugs
Crankcase Breather
Intake hose
Vaccum tested several times (now solid)
Air filter
Sports Cat
Intercooler

Running stage 0

 

[The Sasquatch]

 

[The Sasquatch]

https://datazap.me/u/sasquatch/issue-appears-be-related-throttle-position?log=0&data=2-4-15-17

 

[Richm240xi]

Bump, I’m having a similar issue, you ever figure it out?

 

[bernardo774]

you forget the Boost Target in log parameters.

sounds like wastgate solenoide problem, this do overboost and the throttle closes to maintain the boost target

 

[The Sasquatch]

Bump, I’m having a similar issue, you ever figure it out?

The issue was the turbo pressure converter valve. I've done a write up here, with images of the part:
https://www.spoolstreet.com/threads/throttle-fluctuating_car-went-into-limp-after-this-pull.9424/