E34 morning startup problem

I have a e34 520i (m50) the car started to have problems last winter when it started to get cold it became increasingly hard to start in the mornings and finaly refused . after changing coils,plugs unplugging airflow (maf) nothing would help in the morning (would eventualy start after a long time) finaly unplugged the crankshaft position sensor and it started after about 2 seconds.( Ive been running likre this until yesterday)I changed the sensor but it still doesnt want to start in the morning unless I unplug it..(once warmed up I can plug it bak in and starts and runs beautifuly) I dont know what else to do =B4maybe change the ecu or the relay (anybody have any ideas) thanks.Oz