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Location:
UK
Registered:
May 2002
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1JZ autobox.. help .
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Tue, 04 March 2003 16:38
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I have a 1JZ JZA70 with A342E gearbox, and cannot powerlaunch, cannot spin the rears and get appalingly slow starts. At first i thought i had a gearbox fault , but i am now looking at the possibility that the gearbox ECU is doing something to the engine on takeoff(to allow for smoother launches). The basis for this is the fact that on a lauch, or when raising the revs with my foot on the brake i *cannot* make any positive boost.. my gauge reads *exactly* 0 psi at 2400 revs with my foot on the brake... meaning no positive boost, no powerlaunches, no quick takeoffs and no rear spinning wheels.
Engine and turbo are fine and im certain everything is as it should be.
So.. do any of the A34*E series retard the ignition or prevent the engine from making boost in the primary stages of a launch? Is this why iget such appalingly slow starts? Can there be another reason? Couldii have poor line pressure to the box? What can i do?
DOES ANYBODY HAVE AN A342E !!!!!!???????? DOES IT DO THE SAME ???? AM I THE ONLY PERSON IN THE WORLD WHO HAS EVER QUESTIONED THIS BOX? HELP !!!!!!
Sorry to shout, but ive been searching for info on this box for over a year, and come up with absolutely nothing. I've tried Toyota UK, loads of import places, japanese sites, Toyota JP.. the list goes on. Info on this box is *IMPOSSIBLE* to find, and believe me ive tried... and before anyone says its just an A340E with different ratios.. it isnt. I just want to find out if i have a problem. Should i be able to spinthe rears whilst power braking? Should i be able to make positive boost whilst powerbraking? Is everyones lauch with this box so slow?
Please help !!
There is a video of my dash during a launch at
http://www.jzasupra.com/supra2.avi
You can see how long it takes to get to 30 and how it suddenly hooks up afterwards (i back off about 80). I have hybrids but cannot put the problem down to this as it was the same on standard turbos. Oh, and its running 100% T-IV.
adi
1992 JDM JZA70 'limited'
[Updated on: Tue, 04 March 2003 16:39]
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Location:
Wollongong
Registered:
May 2002
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Re: 1JZ autobox.. help .
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Wed, 05 March 2003 00:27
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I recall reading somewhere in the JZA80 Supra manual that the gearbox has an anti-launch function in the ECU which doesn't allow power launches. It may exist in the JZA70 as well, or I could be full of crap.
I'll have to try find the manual and find the page again before I can be 100% certain of my above comment.
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Location:
UK
Registered:
May 2002
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Re: 1JZ autobox.. help .
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Wed, 05 March 2003 07:18
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I have a manual jza70, however a mate of mine (SYC01J), has had a boosted jza70 auto for a couple of years.
I assure you when this car was auto ( now converted) it had no probs frying the tyres off the line. I think with good tyres it would launch at 2800 with just a hint of wheelspin.
But certainly no problem about not enough wheelspin or boost production on a power launch, quite the opposite.
All this with 295/30/18 pirelli p-zero's on the rear !!!
Matt
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Location:
UK
Registered:
May 2002
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Re: 1JZ autobox.. help .
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Wed, 05 March 2003 11:44
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hmmm cheers for this.. I was beginning to think i didnt have an autobox problem and it was down to something else.. maybe i was right in the first place.
The problem is that there just arent enough of these cars around to make a comparison against.
Cheers
adi
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Location:
Montrose, VIC
Registered:
May 2002
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Re: 1JZ autobox.. help .
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Wed, 05 March 2003 13:25
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Has the box had a hard life, and maybe a good cooking? A34x's HATE being cooked, so maybe it's just the clutches slipping/insufficient line pressure.
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I supported Toymods
Location:
Perth WA
Registered:
May 2002
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Re: 1JZ autobox.. help .
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Sun, 16 March 2003 13:31
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No problems getting boost by stalling up my trans for me! (Get a big cooler though)
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Location:
UK
Registered:
May 2002
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Re: 1JZ autobox.. help .
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Sun, 16 March 2003 13:55
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Sorry, i forgot to mention im using hybrids !
A lot of info has come to light since posting this. It appears that my box is fine. This is all down to the higher lag caused by the hybrids, and the ignition mapping of the original ECU.
My stall point is 2400, and my turbos dont make any positive boost until 2400 (possibly due to the ignition map)! So thats the culprit. Were currently looking into a way round this.
cheers
adi
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Location:
newcastle
Registered:
June 2002
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Re: 1JZ autobox.. help .
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Mon, 17 March 2003 13:36
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My stock 1j is barely making boost at my 2700 rpm launch .and doesnt start to spin the rears until 2800.But if you let it go at 2800 it launches sideways .
your barely loading the turbos if your stalling it to the same rpm as your actual stall
BIT MAKE SUR OY FIT A BIG TRANNY COOLER THE BOX TEMPS AFTER THESE LAUNCHES IS >>WELL BLOODY HOT .
with decent power youll fry the box without a good BIG cooler
what sort of power are you making???
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Location:
UK
Registered:
May 2002
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