megasquirt turbo post rev limiter rich AFR

Hello

Trigger warning! This involves rev limiter which I've learnt many people hate talking about.

I have a BMW M42 turbo, with a megasquirt k-data ms2 ecu. ("Tuned" by a professional)

It seems to drive fine across the map, except, as soon as it hits rev limiter and it ignition or fuel cuts (tried both to the same result) it seems to almost foul the plugs.

The AFRs up until the limiter seems fine, however, the AFRs post limiter on idle will become very rich about 10.5/0.7λ and it will splutter as if plugs are fouled and either cut out or if it manages to idle for 5- 10 seconds it will run fine again.

Logfile to follow later.

Any ideas appreciated.

Don't worry, The engine isn't cold! Only the clock is not working correctly.

Is there any closed loop fueling, that might be adding fuel when it saw the "non-combustion" lean events of the rev-limiter?

Your boost pressure should drop pretty quickly. Could this put you at a different place in the fuel map?