Am dealing with a 1985 BMW735i. Located in Cochise County, Ariz. at an elevation of about 3700ft. It gets cold at night and warm-hot in the day with up to a 50 degree temperature point spread. The car does not start in the morning cold,when the ambient temperature warms up the car starts just fine and runs quite splendidly. The CHILTONS manuel indicates it could be the coil or ECM. Have bench-tested the coil and it produces spark. Do I need to replace the ECM
(big bucks) which I have gleaned controlls the primary circuit of the ignition coil?
Should it go to the Tucson BMW dealer for a computer code readout before proceeding forward?