okay first of all i had the same problem it and i figured out that it was my distrubitor and it cant be the battery, if it was then you have a bad alternator because you should be able to start your car then take out the battery and it should still run fine thats if there is nothing wrong with your alternator. but ye atake off the cap and check the rotor one more time and make sure its is on the tightly and if you already ordered a new distribuitor then you did the right thing because that will fix your problem.

i would be driving on the highway and then my car would just shut off all of a sudden just like if i were to turn the key and put it in netural then i would have to pull over and then wait like 5 mins and then it would start right up also another way you can tell is if your driving and all of a sudden your tach starts going crazy then you know you need a new distrubitor