I seem to have an electrical problem. Initial start engine cranks over normally. I can drive the car around for a while (half hour to a couple of hours) with no problems. I shutdown the engine and then try to restart, and the engine barely turns over once and then stops. If I jump start with another car, engine turns over and starts okay or if I wait a half hour engine cranks over and starts okay. I had the battery checked and found it okay. I had the charging system checked and found it okay. I'm thinking it may be the voltage regular and plan to replace it. Any other thoughts of what is going on?

John