bmw 320 diesel - starting issues - mik nik

HELP PLEASE
i am new to this but need some help. i have a bmw 320 diesel 1999 that wont start. i was driving and the engine cut out as if no fuel. mechanic found no fuel going to injecters so replaced the fuel pump as pressure was very low in pump. it now has fuel to engine but still wont start, tried a new crank senser today but still no good, turns over wont start. diagnostics wont pick anything up as computer thingy wont work. previous to this i had a problem with it losing power on a longer run as if it was gonna stall then blow blueish smoke out and off it went again. it has had a new air and fuel filter
thans for reading please help.:

bmw 320 diesel - starting issues - skidpan

Take it to a diesel specialist that knows what they are doing.

bmw 320 diesel - starting issues - mickeybo

Would'nt do any harm to check out main engine control relay at ecu plug theres 5 ecu plugs on this model marked a-b-c-d-e on the A plug disconnected

A1 key off ov's A1 key on 12v's A8 key off ov's A8 key on 12v 's A9 key off 12v's A9 key on ov's