Nightmare cut out

[JasparRivers]

Have had this problem for a few months and am slowly finding my self rebuilding the car. 1990 316i - will do 200 miles like yesterday and then suddently suffer a serious power loss, splutering and jerking and can cut out all together. Have replaces all sparks, HT leads, distributor, ECU, AFM, and this weekend the coil. This happened on the A3 at high speed with no hard sholder - v.v.unnerving, had to hit the curb at some speed after wresseling with it for a 500 metres and warning those behind me with my flashers.

Before the coil was changed, the car would just cut out like someone had turned off the ignition, but now it splutters, and feels like a different sort of problem. The car then will restart as normal.
A separate problem is that it is overheating with the viscous coupling for the fan failing, but have been running the excess hot air through the car's interiour vents to keep it at normal operating temperature. Have also noticed that occasionally the rev needle will just stick at 2300 rpm regardless of the engine speed - not sure if related. Am at my wits end on this car - ANY more suggestions would be appreciated, as I will soon have to cease to be an E30 owner if it carries on...

Jaspar

[JasparRivers]

and also the engine seems to sometimes rev at 1500 rpm when warm and it should be doing just under 1000

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