My M3W runs well on the road and ticks over evenly.
The problem I have is starting it nine times out of ten.
It seems that the car is over fueling at starting and simply "flooding".
I have a strong spark and fitted new NGK plugs in case.
I have had the car for some years and have fitted a Walbro pump and new crank position sensor in the past.
I suspected that the E5 fuel could be old so I pumped out the old and half filled the tank with new fuel.
Although it sounds a bit of a hooligan trick to try, if I pull the pump fuse out on a flooded engine, and crank it over it will usually start and run, if I immediately push the fuse back in the car keep running perfectly.
I have been on a thirty mile run using the above method, with no running issues
It seems I have a starting over fueling problem. Any ideas or suggestions please?