Alfa Romeo Repair: Alfa 75 TS idle problem, alfa 75, position switch

Question
Hey

I have a little problem with the idle on my Alfa 75 twin spark from 1988.
I have to opperate the gas pedal to start the engine. when it starts you have to opperate the gas pedal again, or it will stall. then after a few seconds, or other times maybe two minutes it will idle right(when not opperating the gas). But when driving the car and take it out of gear it will be unstabile again(but not stalling).
When unstabile it is switching from 1500 to 500 o/min, and is near dying.
I think it is the idle motor, but I am not sure.
And it costs a damn lot of money in Denmark, so I want to be a little more sure.

I hope that you can help,
Pleace send an email, Thanks

Answer
The first thing to do is take apart the throttel body and idle motor and clean with isapropyl alcohol or brake cleaner.

Also check cleanness of battery cable connections and the condition of the battery.

Next use a digital multi-meter (DMM) to check the action of the throttle position switch.