190e 2.3 cold start starting coolant temperature sensor
 

Just wanted to add my information to the database here. I had been having a cold start problem with my 1988 190 2.3. Every morning it was hard to start but the rest of the day it would start ok. It turned out that it was in fact the coolant temperature sensor that had gone bad. I could not find the gentelmans post helping me to thank him so I will post it here. This is a great site thanks.