I have a 96 Z3 with a transplanted 98' M3 S52 in it.
Ever since I have owned it, it has always taken 3 times to crank. Basically, turn the key and spin the engine, turn it off, turn on and spin, turn off and then turn it on again and it starts and runs perfectly.
Just recently it has been taking doing the on/off on/off on/off switching for as many as 20+ times before it starts and once again runs perfectly. It almost seems like it may never run and then when you've almost given up it starts.
I have replaced the fuel pump (had a bad Gauge sending unit anyways)
Replaced the fuel filter
Replaced the Crank Position Sensor
I have then tried to reset the computer. I unplugged the negative on the batteyr and turned on the flashers to drain it.
After this it started on the first try for 3 times and then it went back to not wanting to start.
It seems to be getting worse to where it almost won't start.
Could this be the DME or a bad ECU?