Subaru Repair: 91 Subaru Loyale, subaru loyale, vacuum modulator

Question
My Subaru has been backfiring while accelerating up hill for over a week, and small sparks were visible under the distributor cap.  I checked the oil levels and noticed the transmission oil was extremely low, which I replaced with 1 quart of oil. Within 15 minutes of driving the car, I waited for a light change and the car began to smoke a little under the hood and it slowed to a halt. I tried to restart it with no success.  It would not turn over,and eventually drained the battery trying.  I think it's the ignition coil. What do you think?

Answer
The coil doesn't ail that often.  Take the distributor cap off and note the position of the distributor rotor.  then crank the vehicle over and if the rotor does not move than the left side timing belt is broken.  As far as smoke after the Trans was filled up most likely the vacuum modulator for the transmission is defective and the engine is sucking in transmission fluid.  When the sparks were seen under the cap did you replace it?