Interesting Transmission(auto) Issues

[SOHCSE]

Hey all new guy here-I recently purchased a 1990 240sx SE with 95,000 miles on it. Thing runs like a top with a few exceptions.

First issue:After the car sits for a while (12hrs+) it will refuse to go into overdrive. This will last for about 5-10 miles normally. I have checked the transmission fluid (full and clean). After it warms up, it seems to be fine.

Second issue:While reversing, the car will suddenly feel like the rear brakes have been engaged and gives a lot of resistance. I have checked the pads, rotors (fine) and the calipers (no seizing, move freely) so Im thinking it may be the transmission.

I plan on doing a manual swap this winter while I pamper this fun little car in the garage, but these issues are driving me insane right now.

Any ideas?

Thanks!

[gepeto]

For your brakes...

I think these slider pins that allow the calipers to move might be rusty... change them and lubricate well (I don't know the real name..but you knoew, those two pins on which the caliper slide?)

For the OD problem... no idea... do a manual swap

[1991S13]

Welcome to NICO...

Mine did the same thing when I had my automatic. It acted like that for about 3 months, only during the coldest months, then the transmission went out. I don't know if it hesitating to go into OD had anything to do with it.

Can't go wrong with the manual swap...

[KADreams]

Some auto transmissions have a sensor that will disable overdrive if the temperature of the transmission is below 0 degrees F. If the sensor fails or the harness connector to it corrodes it may incorrectly read the temperature and lock out overdrive.

[Golden]

Try unpluging the gray thing to the back-left of your air filter box. I got this idea off this site somewhere. Mine says JECS on it. It simply disables the car's "comfortable shifting" Doesn't affect the shift performance under hard acceleration as I had hoped. Give this a try because it's free, easy, and might just work.

[Nisman]

Yeah, when I first got my 240 the 2nd gear didn't work. I decided to blow the trans and rebuilt it. After a couple of N-bombs and drifts, the trans went into 3rd only. Got my trans rebuilt with a shift kit. Now it really shifts with all of the gears. From my experience your trans is going into a downhill spiral. You should change it soon before your car goes into 3rd only. Good Luck.

[SOHCSE]

Thanks for the advice all.

(btw it is far from cold here, it does it in 65-70 F weather)

I hope it holds out till winter when it will be parked and getting the manual. Winter is when I get to break out the '67 V-Dub. Oh and Ill check that sensor too (if there is one)

SOHCSE

[Golden]

its a SOHCSE, it's there. It has a gray base and a couple of wires coming out of the plug. Just unplug it and wedge it under there so it won't flop around. Driver side engine compartment, up near hood to the left and rear of the air filter box.

[1991S13]

I doubt unplugging that sensor works...

It's been discussed on here quite a few times, and most people say stay away from it. If you are afraid your transmission is going to go out on you now, it would only make sense that unplugging a sensor to make it bang into every gear would make it worse. I don't remember exactly what that is for, but its something about regulating the amount of fluid in the torque converter...

People also tested if you actually got any gains out of it (in the 1/4 mile) and it didn't help them.

[Florida240sx]

What about the revolution speed sensor?Up under the dash it's a gray plug.Big article about it on here somewhere.It's a sticky.Only will work if your speedo still works.By unpluggin it it goes to it's back up which is your speed.So it will shift fine again.But usually it only affected lower gears.

[SOHCSE]

What about the revolution speed sensor?Up under the dash it's a gray plug.Big article about it on here somewhere.It's a sticky.Only will work if your speedo still works.By unpluggin it it goes to it's back up which is your speed.So it will shift fine again.But usually it only affected lower gears.

Im gonna run a search on that sticky. Thanx, oh and dont worry, didnt have the ball$ to pull the sensor under the hood, I like being able to drive it, too dang hot to lose a transmission and have to pull out the bug (no ac)!