SO I broke a piston in my 2007 r56s put new pistons rings and bearings in it and when I fired it back up it is is revving between 1500 and 2k and running very rich. Drove it down the road and it would pop and smack and then run smooth, almost like I had water in the tank.( I was trying to do pulls to seat the rings.) It was late so brought home parked it.
Fired up today still doing same thing. When it first started it was idling around 900 rpm but soon as i gave it fuel it stated surging again this time it was going between 1800 and 2200
I pulled codes getting footwell module 2 code and a DME engine electronics code. Ive erased codes and they just come back after car runs a few minutes. Plugs are all black as its running super rich. put in new plugs runs the same.
Ive had tune done to it, it has bigger 42 mm turbo, and have a forge BOV, Im using foxwell tool to check codes.
Before I rebuilt it was still running find just no power as cylinder 4 piston was broke .
I looked all over and dont see any wires I might have missed, to see anymore in depth Ill have to start pulling it back apart.
thanks for your help