when warming up.

540i RHD, 1994 model.
Warm car up for a minute, drive off, nice and gentle for 10 mins or so, engine temp comes up quick as I have new thermostat, g/box is freshly rebuilt and running sweet, car itself runs sweet, but if you try to accelerate too hard before the car has been driving at least 30mins, it cuts out violently on acceleration, usually around the 3500-4500rpm mark, like someone is turning the ignition on and off, or the ASC valve is closing and opening rapidly. Once really hot no issues.

I thought it might be the Crank Angle sensor at first, it was new a couple of years ago, genuine, swapped it over and no difference so swapped it back.

Borrowed an old computer from my mechanic and hooked it up cold, the temp sensor is reading ok, 17 deg C cold and 3.7 ohms, within 5-7 mins of idling its at 60 deg C and 1.8 ohms.

Someone must have some idea on what else to check that could be causing this, its very damaging to the driveline if I forgot and push it a little before its been running 30 mins.