Boost problem code P112F

[NickSearle135]

Hello all,

I have a manual 135i N54 and I installed JB4 to it a few months back and it worked fine for a month or so. Recently on gradual acceleration, the boost would be very jumpy dropping by about 5psi of boost then jump back up. It would also throw up an engine malfunction code and put it in power limitation. When acceleration hard it seemed to be fine, I change both the boost solenoids and that didn't fix the problem.

I plugged in a code reader and that gave me the code P112F which is - "code indicates that there was an incorrect correlation between throttle angle (how far down is your accelerator which causes the throttle plate to open) and the subsequent pressure inside the manifold"

I removed the JB4 and the boost has stopped jumping about but the car still doesn't feel right, it feels like it accelerates harder than what you are accelerating on the pedal. I didn't know if anyone has any ideas or has come across this problem before?

Sorry for the long-winded post.
Thanks.

[ErvGotti]

Having a N54 if you haven't replaced your vacuum lines yet I would suggest doing so. The lines are known to crack due to age/heat and will cause boost issues. Even if it doesn't solve your issue, it is still good maintenance.