AUTO trans problem...plz help

[pearl14]

My 1993 240sx has a automatic transmission that has a hard time shifting only once a day. Meaning I will put it in drive and maybe drive about four blocks and then it will have a hard time going from first to second gear. So I have to pull over put it in park, turn off the car and start it back up and it shifts fine the whole day. It only does that once a day. Does anyone know what would cause an other wise perfectly working transmission to do that? I even had the trans flushed and changed the filter..

[OutToWinPAHC]

Ehh could be a number of things. Check the controller wiring, and fluid level. It may be time for a filter, gasket, flush.

[pearl14]

Ehh could be a number of things. Check the controller wiring, and fluid level. It may be time for a filter, gasket, flush.

Already did a full flush and filter...are there sensors or wires that i should check?

[phatsentra96]

Just my personal opinion, since my only 240 atm is dedicated to dragstrip and nowhere road legal, I have similar issues with mine. If the car is cold, mine shifts between 1st and 2nd very hard, but once it warms up a little its just fine. Every nissan I have owned has done this for some reason.

Couple questions for thought:
What kind of mileage is on the transmission?
Are you a turn it on and go or a turn it on, warm it up, then go type of person?
Did you personally do filter change and fill?
(Reason asked is while the cover was off, did you make sure to let it drain for sufficient time, did you look at the servos/wiring before putting the filter and stuff back?)

Also, one idea that I have come accustomed to is when you fill the transmission fluid back up, use some of the Lucas transmission fluid supplement in place of some of your transmission fluid. This stuff works wonders and can smooth out a cranky transmission big time. But for warned, first startup it may take a little while for the transmission to start working as the new fluid/lucas has to go through all the lines and get mixed up to a proper mix. Dad screwed up and threw the Lucas in first then ATF, instead of putting in some ATF, and slowly milking the Lucas in as to not overload the lines because the Lucas is VERY thick and needs to be thinned out with regular ATF some before becoming effective. I'm just giving a few ideas as I honestly have no clue why a transmission would act like yours but also, do consider that the auto trannys have a ballast resistor in front of the drivers side wheel well under the hood and that also could be causing problems, as its resistance is what controls the line pressure to the transmission. Also was there anything on the magnet in the transmission pan like metal shavings or bigger pieces?

[pearl14]

i have a pretty good habit of letting her warm up before putting it in gear. I got about 168k on the trans, have no leaks or any other problems but that shift issue..I had a very reputable shop do the flush and they actually threw in the lucas additive for me when I had the flush done. I would like to learn more about this ballast resistor..if anyone has a picture of it that would be great. I have a feeling its some sort of a sensor or relay related problem and not a mechanical. because the trans shifts perfect, its just that once everyday it will get stuck in gear and i have to turn it off for a second and then start it up, put it back in gear, then everything is fine til the next day.

[elo240]

Sounds like the revolution sensor. I had the same problem with mine not wanting to shift into 2nd sometimes. Here is what i did. On the side of the relay box that on the passenger side of the car, next to the battery is a series of plugs. disconnect the top one, this is the one that goes to the revolution sensor. drive car if problem goes away then you can either fix the sensor or just leave it unplug, which is what i did.

[pearl14]

Sounds like the revolution sensor. I had the same problem with mine not wanting to shift into 2nd sometimes. Here is what i did. On the side of the relay box that on the passenger side of the car, next to the battery is a series of plugs. disconnect the top one, this is the one that goes to the revolution sensor. drive car if problem goes away then you can either fix the sensor or just leave it unplug, which is what i did.

Thank you very much. I will check that out.

[vmiramon69]

i too have the same issue and im bout to check it out and remove that sensor
will post back with results

[vmiramon69]

i tried this and my car didnt shift at all
guess i need a new one

[pearl14]

i tried this and my car didnt shift at all
guess i need a new one

Really? I'm going to try mine and see what happens...

[vmiramon69]

anything happend?

[elo240]

Sorry that didn't work for you. heres the tread that i found all my info in. maybe you can find some answers there.
94-240-conv-with-at-shift-problems-t96505.html

[pearl14]

Sorry that didn't work for you. heres the tread that i found all my info in. maybe you can find some answers there.
94-240-conv-with-at-shift-problems-t96505.html

Thank you very much for all your help and that link! I just unplugged my revolution sensor and its been shifting perfect ever since.

[elo240]

Glad it worked for you!