Right my car will still only do 120mph. But i have now noticed that it is not changing up to 4th gear:rolleyes: any idea what might be causing this. The car had just had a brand new auto box the week before i got it in september, with a new ecu and everything.

Could it be something simple. (yeah right)

Is it a Jap car with a 112mph speed limiter (and an inaccurate speedo) ?

 

 

Originally posted by keith s

Right my car will still only do 120mph. But i have now noticed that it is not changing up to 4th gear:rolleyes: any idea what might be causing this. The car had just had a brand new auto box the week before i got it in september, with a new ecu and everything.

Could it be something simple. (yeah right)

No the car is UK. But apparently the car is fitted with boost jets & a re-mapped ecu.

If it's not changing into 4th and the gearbox was just changed before you got it, it sounds as if the gearbox has a fault, it may not have been installed properly or have an internal or control fault, do a diagnostic on the box and see if you get any fault codes, there is a technical article on this in 300zx.org.uk somewhere.

 

Oh, and by the way, don't drive about at 120mph for too long in 3rd or you will definately need a new gearbox!!

 

Paul N.:D

Is that with the overdrive on or off,just wondering,had same prob on me previous zed for a day or so,then it cleared after using o/d on and of for a day,cleared up then,dont ask why,maybe just luck!;)

Overdrive ON

How do i do the auto box diagnostic.

http://www.300zx.org.uk/tech_09.htm

 

Go to the above web site and follow the instructions!!

 

Hope it helps

 

Paul N

does it also return to almost idle speed when you take your foot off the gas i. e. no engine braking?

If so it is almost certainly a loose or broken connection on one of the wires to auto box ecu.

You will have to get a pin test done at an Autbox specialist.

Hope thats all it is , as this is what happened to me.

:rolleyes:

YES my car does this, when im doing any speed if i take my foot off the accelarator the revs just drop to the bottom.

Almost certainly a broken wire or loose connection on Auto ECU.

As prviuos post you need competent Auto box specialist to check it out. I used QAS in Bristol.

It took them a week to find after checking everything else, including cluthes and solenoids.

So hopefully yours wont be so expensive if you point them in right direction.

The fault does not show up on the diog. test.

The Specialist must have all the electronic diog. equipment to do the pin tests etc.

Hope you get it sorted soon.