My stock hatchback runs very well and will not miss a beat all day long in the Las Vegas heat. Having replaced nearly the entire system. the a/c is in excellent condition. Problem is I can't have both running at the same time or she'll die after a few miles. After that she'll turn over but won't start, then about an hour later she'll start right up like nothing happened. Some symptons before it happens are wildly fluctuating rpms, loud valve knocking, power loss and such. Any thoughts out there will be most appreciated.

 

It sounds like a heat related electrical problem.The ignition system to be more exact.Look at the coil and the ignition module.

 

Its the ignition box on the fender well they were known for that .when they get hoy it will die then when it cools down it starts right back up