I think the idea of the full throttle switch is very interesting. KE-Jetronic uses a valve to modulate fuel presure when you are in closed loop mode. That is how they fine tune the mixture. For a simple test, I would hook up another switch to mimic the throttle switch, but have it in the cabin by you. When the car begins to act up you could just hit the switch without stepping on the gas any harder. This would limit how many things you are changing at one time and help figure out where the problem is. Having the meter to monitor the O2 sensor at the same time could be real instructive. I love K and KE Jetronic systems. Only thing I hate about them are the prices of parts.