Cadillac Repair: 4.1 L engine idle speed control, vacuum leaks, hi doug

Question
Sir is there a easy way to set the idle speed control of my 86 Cad Eldorado 4.1 L engine?  
I know that turning down the plunger of the idle speed control motor will reduce the idle by a few rpm's, but not down to to the 700-750 range.
Right now the car is at 950 with the plunger screwed down as far as it will go.

Any help will be appreciated.
The Air Con does not work on this car.

Thank You
I appreciate your help

Answer
Hi Doug, This is a multi step process in that the engine is wamed up to operating temp. and the timing is checked, base idle speed, tps and then the isc motor. If any of the other adjustments are off then it might make the computor set the idle speed higher. Also vacuum leaks will cause a higher idle. If those checks and adjustments don't return the idle to a normal speed then further testing of the sensors and fuel pressure will need to be done. Bill