[Gunter]

Isopropanol is Rubbing Alcohol, available in any grocery store/pharmacy.
Mark: What exactly do you mean by: Sensor?
I don't see how cleaning the airflow plate with rubbing alcohol would make any difference. When this plate sticks, it means that it misadjusted and rubs against the throttle body.
Rodney: Before you replace any hoses, ask your mechanic if he thinks a quick check for a vacuum leak might help. However, a vacuum leak shows up as rough idle. If you don't have that, it sounds to me a matter of timing, idle speed, and mixture.
Is the retard on the distributor connected and working?
Can you let the mechanic confirm that the set-up (Vacuum lines) is unmolested and strictly stock?
On these engines, there are so many vacuum lines; add to the above the brake booster (Servo) line coming from the TB and going to the front.