My 240 transmission

[LTZRNNEM]

why would my auto transmission be shifting hard sometimes and shifting good the next....its kind of a pulling feeling like a jerk.....

[KASilvia90]

It could be a sign of your transmission showing its age. Does it do it based on temperature or any old time? It can be common if it is cold until it warms up. If it is like that then go out and buy a bottle of lucas transmission fix and put half bottle in it. Mine was like that when I bought my car and that fixed it. Couldnt kill it actually...

Something else, If this is for your 240SX, There is a resistor sitting on that bracket inside the red square on the pictire posted. Its only on the A/T's and I dont have any pics from when mine was there but its a rectuangular things little smaller than a thumb and if its not too worn says JECS on the side of it. Check the wiring and connections going to it, it could be loose. That comminicates with the auto-brainbox and tells it pressure/temp or something. If its not connected the car will jolt into gear kinda like a sport-shift mode. I put a toggle switch on it and used to have sport/comfort shifting mode.

There can be other things but thats the two most likely. There is a way to enter a diagnostic mode, the OD off light flashes and reads codes, I just dont know how to enter/use it.