Hi I have a 300zx turbo 1990. It has started having problems automatically changing gear. Have to take foot off accelerator a bit for it to change.topped up the gearbox fluid but no different. wondering if anyone has any ideas what it could be?

The Auto boxes are prone to fail im afraid, if you do a search you will see a fair amount of posts on the matter!!

 

What was the fluid like ie: colour ? and have you checked the oil for metal shavings etc:)

Do these boxes have a filter in them?? If so, flush it out and fill with now oil.

Mine does it when its cold, bit better when warmed up. I had the oil changed and not much of a great difference. Could be the torque convertor on its way out or a solenoid, not enough oil pressure maybe.

Thats why im having a manual fitted soon.

Changing the gearbox oil will be a good place to start, clean the filter, the only problem being you wont get all the oil out as the torque convertor holds a fair bit of it.

Good luck

Hi I have a 300zx turbo 1990. It has started having problems automatically changing gear. Have to take foot off accelerator a bit for it to change.topped up the gearbox fluid but no different. wondering if anyone has any ideas what it could be?

 

Auto box can display similar faults to what you have and mostly ends up in higher gears been lost and eventually a totally failed autobox.

 

However assuming you still have all gears but need to coax the gearbox to change into them by varing the throttle input then it is possibly an incorrect setting or poor connection on the throttle position sensor (tps).

 

The tps should be your first call, the black box fitted to the passenger side of the engine on throttle butterfly spindle, it has two cable connection on it, one directly plugged in to it and one on a flylead.

 

The setting is very important to the crisp change of the auto box, also a poor connection can give a corrupted signal and so firstly try disconnecting the plugs, clean with WD40 or similar and reconnect and test.

 

If that does not work the tps setting will need to be checked, do a search for actual way to do this using a test meter, or if someone close by has a ConZult diagnostic then that`s the way to go.

 

So dont` despair yet it may just be the adjustment / bad connection and will cost you nothing to fix.

 

 

Jeff TT

Do these boxes have a filter in them?? If so, flush it out and fill with now oil.

there is a filter inside the box will need to remove the gearbox sump pan first.

Thanks Jeff

Of course i forgot about the TPS setting, mine is slightly out and maybe the main cause of the gear change problem

convert to manual, and be done with it ;)

ok thanks for all your help. will try the tps over the next couple of days and will let you know the result

ok mate thanks. will try that over next couple of days and let you know the result. how do i book the free assesment and report you mention in your message?

ok mate thanks. will try that over next couple of days and let you know the result. how do i book the free assesment and report you mention in your message?

 

Easy just subscribe to the forum to be eligable, then send me a private message or call me at the workshop number via our web site.

 

Jeff TT