1982 245GL wagon B230E - Misfires upon starting??????

Hi all

When started from cold my 245 runs very rough at very low revs
(~500rpm) for about 5 to 10 seconds, before suddenly smoothing out to
900rpm. It is an immedite transition from stumbling to smooth.
Sometimes the engine starts then immeditely stalls. Never takes more
than 2 goes to get it to run smooth, so it is not as if it is a
disaster, but I would like to fix it. Previously it used to start
first go at 900rpm, maybe a bit more.

This all started after I cleaned my throttle body. After cleaning the
idle speed went up to 1100rpm or more it the knurled adjuster turned
right out. I had to adjust the idle stop screw to get it back down to
900 or so.

I live in Sydney, Aus where temps rarely get below 10 degrees C
overnight. Most starting would be done at the moment at about 13 to 15
degrees C in the morning.

This is K jet fuel inj.

All help really appreciated

Chris