Gearbox conversion. Most will think its crazy, but i want to convert my 1992 Celica from manual to Auto! My girlfriend cant drive stick & i have access to a good auto very cheap, but whats involved? do i need to change the ECU? The "why bother doing it" answer is really not very helpful to me, sound technical advice would be appreciated.

There used to be a long- running joke among auto forums and clubs about advising someone to check one's "blinker fluid", if having trouble with their turn signals not working... So you can see the quandary you have put me in: what kind of fluid exactly are we talking about here? . I am so-so familiar with celicas, owned a pretty decent riding '89 (or '87, maybe) model for a short while, ran smooth as ice down the interstate at 80 mph on the initial ride home, but it was def. a beater- had seen better days by the time I bought it for less than $400...yes, better days...8 months later it went to a shadowy grave, due to clipping a wild animal at night. I have no regrets.
If it is conventional fluid to any under hood part, it makes no difference between a convertible and a coupe. The celica generation that included your 1992 model, was the one most enthusiasts favored, on a celica forum I once joined. They sure made fun of Honda owners- calling the accord a grocery-getter...

name the fault.
tell the symptoms, there are like 100';s
A/T or M/T
auto or stick
can you drive it?
do all gears work? (car moves in all gears with out RPM going crazy high)
gears grind.
cant shift at all?
what?

Open the hood up. You will find two different types of sticks, one near the alternator to the belts side, which is yellow or white colored and one on the battery side. It is orange colored, round small cup like dip stick, secured with a safety lock on it. Press the lock a side with your thump and take the stick out. When you push the stick inside it will sit in place firmly with a click sound.
You can add the Automatic Transmission Fluid (ATF) here.

Check for high back pressure in the exhaust system....blocked catalytic converter.

To test...remove the front Oxygen Sensor and road test. It will be a bit loud, but your not driving far.
If it accelerates quicker, you have blocked cat'.

If not, you may have a failed torque converter or slipping transmission drum or clutch assembly if an automatic..

weird one this ,you mean a manual clutch ,stick change ?? right taking the **** over down to work ,i dont think this is a clutch fault unless its fallen apart inside the bell housing ,i think the problem here is the gearbox ,or a drive shaft ,but upon re-reading your question and its in neutral as well then i thjink its the gearbox seized up ,if it is then as its 1992 vehicle its not wotrh repairing ,it only has a resale value of around 1000euros and another gearbox from the scrapyard will cost at least 300 euros plus a new clutch at the same time which is another 180 euros or there abouts plus the time factor involved its just an un economic repair on such an old vehicle

if this car is AUTO the dipstick will be on the same side as the gearbox underneath the hood. clearly marked with a red (i think) coloured plastic handle you check the level with the engine running and in park. if MANUAL gearbox then look down the front of the gearbox and about half way up theres a hexagon drive level plug - 8mm allen key hex i think - remove this and fill till oil runs out with engine off.

think the torque converter has died a death ,but you will have to remove the gearbox to have a look

never heard of this ??speed sensor would only control the gearchange of the gearbox not engine performance ,well i would have thought so but ????.What country you in to get away with changing the gearbox from auto to manual????definatly not spain

make sure brake pedal is depressed. ckeck for blown fuses/faulty brake switch

u will find it hard to buy a used auto box to fit this car, and remember u will have to change the gearbox mounts fit a different pedal box and modify where the gear selector mounts for a manual gearbox conversion. to much hassle for such little gain better off buying another car