93 240sx conv. automatic shifting problem

[mottabam]

Have owned since new a 240sx convertible 93. When the car goes from first to second gear sometimes nothing happens. The rpms will rev up but it is like it is not in gear and not accelerating. If I immediately shut the car off and re-start it will shift fine. It doesn't do this everyday but apprx. 2-3 times a week. I have had several shops check it out but the problem would not show up when they would drive it. Any suggestions would be helpful.

[VanNelson]

A problem that plagues 240's of yours age is that the revolution sensor begins to go faulty, then fail. This causes the car shift erraticaly, or not at all, usually when shifting from 1st to 2nd. To find out if this is it, disconnect your rev sensor by unplugging it, and taking a test drive. If the problem disappears, then its your rev sensor, and you'll need to buy a new one. Replacing it isn't hard, and you should be able to do it yourself. If you want more info on where it is, or how to disconnect it, then search the forums, and you should find similar posts where it is explained.