i have a 95 sable with a 3.0 and i am a mail carrier so i do alot of stop and go all day long. towards the end of the day when im about done my car will shut down and leave me sitting where ever i am at for about 30 mins then it will fire back up and continue to run. the gauges are all good its not everheating or anything it will just shut down completely and after a while it will start back up. any ideas??????