924 Starting problems

[Willem]

Please help: My 1981 924 (Automatic) is giving me problems with starting it. This is not a consistant problem as the car does start most of the time - only once-and-again it refuses to start.

I have replaced the coil with a new one, but the problem seems that there is no spark coming from the coil lead to the destributor. Testing terminal 15 (+) of the coil gives only 1.2V when switched on and only 2.3V when attemting to start the vehicle.

Terminal 1 (-) of the coil gives a 7V reading when ignition is switched on - and the connector (connector no. 4 on the plug) to the electronic ignition unit gives a 11.9V reading (very close to battery voltage).

What could be the problem? Are there any quick fixes/checks to be performed? When the car does start there is absolutely no problem at all...

[Willem]

According to my Haynes Workshop Manual on the 924 - if the reading on the (-) terminal of the coil gives a reading in access of 2V, then one will need to replace the electronic ignition control unit.

Thus, according to my results above this should be the case. However, I am also getting a very low voltage reading on the (+) terminal of the coil - according to the workshop manual this should be minimum 5V with the ignition switched on and = to battery voltage when attemting to start the engine.

Having 2x problems as indicated above does not make sence to me as it is highly unlikely that it will develop problems on both sides of the coil (it is a new coil) at the same time...

Or am I incorrect with my analysis? Somebody, please help - surely my problem is not unique to my car allone?