what would be the symptoms of a bad coil and a bad solenoid. the engine remains on for a couple of seconds. it all started ever since the car stopped running for a year. i used a spare coil (a) to see if the one in the car (b) was bad and the engine stayed on i turned off the car and used the one on the car(b) started the engine it didn't turn off. (good) next morning i turn on my car and it stayed running for a couple of second back to the same problem.