Automatic Transmission problems

[aikiwoce]

I've recently been having some issues with the automatic transmission in my 1990 Nissan 240sx LE. It started off as hard shifting from 1st to 2nd, and not shifting into 3rd overdrive until it was warm.

In the past few days it has started to "slip" randomly during acceleration only to catch a second later, sometimes 2-3 times in a row. It also seems to fluctuate between overdrive and the non-overdrive while maintaining maintaining speed. It feels like hitting a series of very small bumps repeatedly while driving down the road. It doesn't really shift out of OD, but it feels like it wants to. The other day it stalled at a Red Light. The problem seems to go away once the engine is warm, but still not completely.

Also, though it may be unrelated, I sometimes have problems starting the car, and have to "jiggle" the shifting handle the neutral switch senses the car is in neutral and able to be started.

What exactly could be causing this issue? Fluid levels, burnt fluid, sensors, loose wiring, and what steps should I take before taking it to a transmission shop?

EDIT: Oops I think I posted this in the wrong forum.

[mattscar]

mine did the same, check your A/T fluid.

[omgdudewtf]

If you need a good transmission I have one.

But check your ATF first, if its low, go ahead and change it and then see how it does.

[aikiwoce]

I've checked the ATF fluid when it was cold, and when it was warm, and it's in the specified ranges. In fact there may be a little more than there should be in there. The fluid is definitely more pinkish/red than reddish brown.

I'd love to drop out the transmission myself, but I have neither the time, nor the place to do such a thing. Now I remember the dealer telling me the transmission had been recently serviced, by the previous owner, when he sold me the car. Something about a spherical/spiral gear orsm. Oh well.

The car is also not in the best of shape, as far as the exterior/transmission are concerned, and I think I'm going to be selling it and looking for a late model s13 or an early model s14. I actually have 2 1990 240sx's sitting here, the other I think I bent the **** out of the connecting rods/valves.

I'll probably make a post over in one of the other forums about it, but the one I'm driving now has a working HUD, and pretty pristine interior.

[BIGT94z]

When in doubt buy my transmission...it's cheap

[aikiwoce]

It appears the problem was the Throttle Positioning Sensor, and completely unrelated to the transmission.

[sleepyRPS13]

^word, it could be flat spots on the tps.

how does the car idle & start ?

[aikiwoce]

Sometimes the car would stall on starting, and randomly at red lights. It also tried accelerating quickly and slowly. There seemed to be several dead spots from the TPS. I could also bump it and the engine would sputter and die.