Goatman
You have been most helpful with your resistence tests and greenbook sources. Several things now lead me to the Ignition ECU. First the fuel pump was not working and I unsuccessfully replaced it with a spare FI ECU only to realise that it was not getting the signal to turn on the pump relay because I had no spark. Secondly, since the car can adjust the timing according to a signal from the knock sensor, the 5v Ignition ECU must control the 12v coil thru the power stage/ ground. And lastly because a replugging often solves the problem it makes me suspicious of a capacitor of which the power stage has none but the ECU has many (I think).
Anyhow this writer must now go on strike to become a reader of the green book that I was able to download and print thanks to you. If I find an answer after digesting and testing I will be sure to post all nutty theories and remedies as it would not surprise me if this is the reason for the demise of many older 740's resulting in many large repair bills. I have not had time to do your resistence tests so the answer maybe there. Does anyone know of an Ignition ECU rebuilder should I decide to go that route?
jmars