BMW Repair: bmw start problem, 1987 bmw 325, resistance test

Question
"I have a 1987 bmw 325 e 2 dr sedan, parked car several days ago and came out to restart and had no spark, tested coil with a static and dynamic test, also both sensors in the bell housing(SPEED AND REFERENCE SENSOR) both function and I at one point removed the reference sensor and ran a piece of metal in front of it to verify it was working, each time I could hear the relays clicking both with the sensor test in the bell housing and with the metal test but still no signal from coil,test light shows coil to be constant closed circut (LIVE WIRE HOT AND REFERENCE WIRE GROUNDED) and no signal or pulse comming from the computer, is there any input signals to the computer, fuses or relays that may be blocking my pulse to the coil but still allowing the refrence sensors to operate the injection and fuel system? everything else seems to function well
pleae help    thanks

Thomas"  

Answer
Hi Thomas,
It is nice to know that there is power and ground to the ignition coil, but you should still disconnect those wires and do a resistance test (the primary wires may be closed circuit but be shorted),just like most coils I think it should have approximately 1 to 3 ohms and the secondary should have approx. 9000 ohms.
The coil primary is powered by the ignition switch naturally, and switched on/grounded by the Motronic engine control module. The module is of course fed a lot of signals
by such things as air inlet temp.,air flow, fuel rate, rpm, reference point sensor, 02 sensor, idle speed, cts, etc. etc. But the engine control module switches on the coil directly (from terminal 1 on module to terminal 1 in coil) so you may want to test for continuity here. You also have to check power and ground to it but it is a fairly complex setup. If you want detailed schematics, give me a fax number and I will fax it to you.
Or give me your name and address and I will mail them.
Regards,
Tino