I thought I had this fixed when I replaced the temp sensor. Still does the same thing but at a lower outdoor temp. Has become a problem since the temp in Ma is dropping.
My 90 Stanza refuses to go into 3rd gear (auto trans) unless the engine is totally up to operating temp. It used to shift into 3rd when I got to about 50 mph on the highway. Now it stays in 2nd for about 10 extra miles at 50 mph. Then shifts into 3rd and will shift correctly for the rest of the day. The same issue begins the next morning if the outside temp is around 30 degrees. The car will not shift into 3rd until it is totally at operating temp.
I have done the plugs, dist cap, plug wires, 02 sensor, temp sensor, even replaced the radiator because it developed a leak, rad cap, and thermostat, checked trans fluid (it was to correct level when car was warm). All this was completed during the summer in preparation for the winter since the car developed the shifting issue at the end of last winter. The car shifted correctly during the summer but now it getting cold again and I am seeing the same non shifting into 3rd problem.
The engine runs fine when cold and warm so I don't believe the shifting problem is related to the engine, but I could be wrong.
I have no error codes but I still believe a sensor is the issue since the car shifts correctly when it is warm. My only thoughts with sensors is they are almost always bypassed when the car is cold. They come into play when the car is at operating temp.
I need some help here, Please
Dan