S13 Automtic transmission problem

SON240sx Automotive
1

i have a 1993 240SX with the ka24d with a automatic transmission from time to time the transmission will lock up in one gear and not shift out, well not until u shut the car off and then restart it?

Wondering if it can be a sensor? or what ideas does anyone have

I dont want to hear that i should have the 5spd swap done…this isnt my car it is my dads, mine already had the 5speed in her

2

Common problem

http://forums.nicoclub.com/zerothread?id=96505

3

my car does that to if you rev it and let the wheels spin ie. when stuck in snow banks and the rev the engine while trying to break loose

4

Check map sensor. There’s 3 things that could be causing that:

  • Throttle position sensor (linked to the throttle valve; ie. the “driver demand” signal to the transmission.

  • speed sensor (linked to the governor in the transmission, which is which is the valve in the transmission that determines the shift point by reading output shaft speed)

  • MAP sensor (linked to the modulator valve in the transmission which senses engine load through high or low vacuum readings)

It seems that the problem may be connected with the governor inside the transmission. It works via centrifugal force. The faster the output shaft spins, the more it would want the transmission to shift (depending on what the other two sensors are reading back to the PCM).

First thing I would recommend is a fluid flush, and replace with new fluids. Clean your TPS and MAP sensor and see how it goes from there.

5

could u ball park me to where they are located on the transmisson?

6

Whoa boy… LOL… They’re all on the valve body :stuck_out_tongue: Modulator valve, governor valve, and throttle valve is all in the valve body (that metal thing that looks like a complicated maze you did for fun in elemetary school).

I’d stick with the fluid flush, TPS and MAP sensor clean-up than even get down and dirty with the tranny. (that sounded wrong). Do the things I said above first. If it doesn’t correct the problem, and you still persist on DIY, then pull out an FSM when you take your tranny apart.

If you don’t wanna rip it apart, you can either live with it or swap in another tranny, either another auto or go straight for a 5 speed swap.