Geo Prizm Engine Hesitate

My 96 Geo Prizm ( Toyota Engine) --it's Engine Flutters Very Slight Hesitation Every 5 Minutes Or So. Just Started Doing This. Well-...

My Temp Gauge Go Down And Rpm Go Up And Heater Stops Blowing Cold Air. But Then Temp Gauge Will Go Up And Rpm Go Down And I Get Hot Air...

I Put Car In Drive It Stalls Or Shuts Down Give It Accelleration It Putts When Car Is In Reverse Theres No Problem