Selespeed problems with RPM
I am peter and i live in the Netherlands
I drive an 156 selespeed 2001
When the car is cold it drives very well,but when the temperature is rising to aproximatly 90degrees C the RPM is going to 1800(when standing stil)
And when i step on the gas and let go,the RPM is increasing very slow . This problem began after changing the thermostat,the old one stayed open so the water temp did not go above 70 C
I have already visited 3 alfa romeo dealers and they all said that i have to replace the ECU,and i am still waiting on an answer from a bosch carservice that i have visited 2 weeks ago....
Is there anyone who is familiar with this problem?