Ken, If the Idle is set ok ( 900 to 950 RPM ) then I would make sure the microswitch screw is screwed in enough to trip the switch. Make sure the connector on the idle speed motor is making good contact. Yes, You will need to replace the TTS switch for cold starting. I have had a similar problem if the air flow /control plunger isn't adjusted properly ( mabe give it 1/4 turn to the right to enrich the system.) The 1/4 turn will raise the control plunger. Also, make sure you have no vacuum leaks. Last would be the warm-up regulator, If it's never been changed it may be shot. That's why it's called warm up regulator due to the control of the fuel pressure when cold. That's my suggestions. John Hervey http://www.specialtauto.com/ << Are there any other thoughts at what may cause this. It appears to be a fuel starvation situation but then it corrects itself and purrs like a DeLorean with no stalling or hesitation. That is the confusing part. The above problems all would or should continue to persist no matter how hot it gets. >>