This is my first winter with my '90 190E 2.3 (M102 8 valve). I have noticed that on the first morning cold start for the last two mornings (among the coldest so far in the suburb of Sydney where I live at around 0 to 2 degrees C), the car has started fine but has idled very fast at around 2000rpm for about 3 to 5 seconds and then suddenly dropped back to the correct idle speed. It has never done this previously whilst I have owned it (nor has our 300TE we have owned for 5 years which also runs KE Jetronic injection). Apart from this minor issue the car is performing fine. It's not that it is a problem, only that I suspect that it is not normal and may be something sticking (idle control valve?). Any ideas?

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107.023: 350SLC, 3-speed auto, icon gold, parchment MBtex (sold 2012 after 29 years ownership).
107.026: 500SLC, 4-speed auto, thistle green, green velour.
124.090: 300TE, 4-speed auto, arctic white, cream-beige MBtex.
201.028: 190E 2.3 Sportline, 5-speed manual, arctic white, blue leather.
201.028: 190E 2.3, 4-speed auto, blue-black, grey MBtex.
201.034: 190E 2.3-16, 5-speed manual, blue-black, black leather.