'89 GP 2.8 / Coolant fan behavior

Got a problem with the fan, I had cold start probs, so I changed the coolant temp sensor, and thought this would also solve the problems with the fan. It turns on at about 140, runs for about 3 minutes, then turns off again, then again turns on at about 180 and runs for about 5 minutes, if the coolant temp reaches 180 again it turns on again, so the car won't get hotter than 180 Fahrenheit. I really don't understand that.

However, the cold start problems I had seem to be gone with the new temp sensor. At least so far.