Ricky Larocque

Hi there, my 4.3l wont stay idling when cold. I have to keep foot on gas pedal to keep it at 1000rpm or else it goes up and down from 900rpm to 200rpm. Or if too cold will just start to stall right away. But 15 min of holding gas pedal to keep rpm at 1000rpm, its warm enough to let go gas pedal and it will stabilize rpm to 750rpm. Once warm, the first try to start always start to stall, turn ignition completely off and turn back on, try starting it again and it would start fine at 750 rpm and stable. I can't pinpoint the problem and at this point i need any help. Thanks