Could be a sensor issue..... Unplug the wiring to the metering head this will make your car run with no electronic enrichment..... DO NOT DRIVE THE CAR WOTH THINGS LIKE THIS AS IT WILL BE LEAN AND COULD MELT YOUR ENGINE.... But hopefully it should improve the situation on idle and will at least point us in a direction to repair it.

If this makes things better its most likely your coolant sensor or throttle position sensor or the wiring to it...