I just removed the throttle body rubber boot and sprayed the throttle blades with carb cleaner, I tok a toothbruch to them and got them clean
I also removed the boot from the air sensor plate (above the air filter) and claned the plate and hte surrounding surface. I took a magent to the center bolt on the plate and lifted it up and cleaned the edges and mating surfaces.
its not running richer or leaner, just 200rpm higher..
as long as you did not mess with the setting on the fuel distributor, then its exactly the same mixture as it was before you cleaned the throttle body..
you can turn the idle back down to where it used to be, with the idle screw.. its pointing towards the firewall on mk1 cars..
you may have not secured one of the boots on fully, resulting in an air leak. the ecu sees lean from the o2 sensor and compensates, resulting in a higher idle.
you can determine your mixture properly with a dwell meter, or just warm the car up, unplug the o2 sensor and measure the voltage.