My 1991 M30 has a rather harsh 1-2 shift when cold, but does the 1-2 fairly smooth when warm. It is also always slow to do a 2-3 shift or to lock up into overdrive unless you back off on the throttle; i.e., if throttle is held steady to hold RPM at 3000, it will not shift unless you back off very slightly on the throttle.
I've checked the TPS functionality and adjustment per the manual and it appears to be within the resistance range and voltage output ranges specified as currently adjusted.
The car only has about 60,000 miles. I've done a transmission flush and filter change, but it didn't change the symptoms. Any ideas as to what could be the cause? Speed sensor?
