I am having problems starting my car. Its been sitting idle for the last 4 months. the car cranks but wont turn over. All tune up parts were replaced last summer, and everything was fine intil the last week. The only part not replaced was the coil. How can I check to see if the coil is good or not. I added some gas line antifreeze to the tank about 2 weeks ago. Sometimes it turns over slightly, but then dies out. Any suggestions?

Thanks