Can't say I am knowledgeable about a 92 D21, but I have completely rebuilt a 89 D21 with the help of this board. If it is a manual then I doubt if it has a torque converter and transmission fluid. I think you will find a clutch plate and clutch doing the "torque converting" job and transmission oil in the gear case. But most importantly, if you want the pro's help then read the codes or get them read at a parts store and then post them so Zane Grey gets involved. That's the first thing he is going ask about. Once he is on the case, or any of the other pro's, then you are on the road to recovery. Also try the search function, lots of good stuff there and you don't have to wait for an answer. The coolant sensor may indeed be a source of trouble if it is throwing too much fuel into an engine that it thinks is cool. Maybe the codes will point you in the right direction. Happy hunting.