Well, cleaning the contact on the cylinder head temperature sensor did not help. But yesterday, after first start in the morning, the car was idling while I was doing something else and twice the revs increased for a short moment and then returned to idle RPM. The second one I watched and the RPM went from around 700 to 1700-1800. I then drove the car to the technician who cleaned the contacts for the electrical connection for the Mass Air Flow Sensor.
I forgot to mention the idle air valve, but will when I next see him.
This is surely a slow, painful process, but as I mentioned, I am no longer interested in changing out parts hoping that we hit on the culprit.
I do appreciate all help as I have already saved money by using your advice.
