GXE10/ 1G-FE auto ETCS disable?

[mattysshop]

just got an auto IS200 for the wife..

firstly, just wanted to say despite what everyone says, they actually arn't that bad!! not as slow as you think..

99% of the time there great, and do the job very nicely...

BUT that 1% of the time you want to take off quickly from the lights or up the freeway onramp is the problem..

in 1st gear, even with pwr on, and tcs off.. it only uses 1/3 or less of the throttle till about 48-4900rpm when it gently opens right up to full throttle..

it's very frustrating as the car accelerates much quicker fully in second, and even third than what it does in 1st!!

the throttle body is a single butterfly, both mechanically operated, and motorised.. so unfortunatly you can't simply 'unplug' it.. even the motorised part comes into play on idle.. it constantly varies the throttle position regardless of external conditions (or pouring upper cylinder cleaner down it) to maintain idle speed.. so it's a pretty well thought out peice of gear..

seems that the VVT 1JZ boys have a similar problem with thier chasers.. but it seems very easy to get around with them... even just simply unscrewing the 2nd butterfly... unplugging the unit etc...

any ideas for the 1G-FE?

[wilbo666]

How have you determined that the throttle is only opening 1/3rd?

1JZ VVTi (and most non VVTi for that matter) have ETCS, not ETCS-i... there is a big difference between ETCS and ETCS-i

1JZ have a normal, fully cable actuated throttle and also have the separate computer controlled traction control throttle.


ETCS-i on the other hand is more complex as you say, there is a 'demand' sensor and a 'feedback' sensor and an electric motor to drive the throttle that is controlled via the engine ECU...

I'm not personally familiar with the IS200 1G-FE setup, but if it is like the 2JZGTE VVTi setup which uses a cable to drive the demand sensor with a small mechanical failsafe then it might be possible to modify the demand sensor / throttle so that you force the throttle open via the failsafe earlier, but this might also make the engine ECU go into failsafe mode (in fact I would suspect it...)...

I guess another option would be to remove the throttle and let the engine ECU move it as normal but have a normal cable controlled throttle in it's place... you would loose the idle control however in this case...

So in summary I'm not aware of any easy ways to solve your problem...

Cheers
Wilbo

[mattysshop]

the 1/3 throttle was a geustimation.. i am only assuming it opens 1/3 - 1/2 at most... as throttle response doesn't change from pressing the pedal about 1/3-1/2 vs full throttle, it seems that it only actually acheives full throttle above 40km/h (almost 5000rpm).. at which point the increase is almost like a large turbo ramping on boost, but with non of the fun..

i'm sure it has something to do with a safely feature for the auto.. gaurd against any possibility of loosing control of the massive 120kw and 200nm of torque etc...

i'm not really wanting to permanantly disable it.. i'm sure it serves it's purpose, but if i could wire in a switch to the TRC, or PWR button to just make the throttle act 1:1... just switch the driving aids off... it would be alot more fun to drive! it seems like a very healthy engine if you boot it trying to overtake someone on the freeway it's fine, whilst no extreme power house it definitly isn't slow then when the throttle is acting somewhat normally...

can you elaborate a little more on the 2JZGTE VVTi setup?

I guess another option would be to remove the throttle and let the engine ECU move it as normal but have a normal cable controlled throttle in it's place... you would loose the idle control however in this case...

this setup only uses a single butterfly

[wilbo666]

the 1/3 throttle was a geustimation.. i am only assuming it opens 1/3 - 1/2 at most... as throttle response doesn't change from pressing the pedal about 1/3-1/2 vs full throttle, it seems that it only actually acheives full throttle above 40km/h (almost 5000rpm).. at which point the increase is almost like a large turbo ramping on boost, but with non of the fun..

If I was in your position I would be tapping a multimeter into the 'actual' / feedback engine ECU TPS on the electronic throttle to find out how open the throttle actually is / isn't getting... it might be getting pretty close to fully open?

can you elaborate a little more on the 2JZGTE VVTi setup?

There is a cable from the pedal to the throttle body 'demand' TPS. The cable moves the demand TPS.

The signal form the demand TPS connects to the engine ECU and the engine ECU moves the throttle to the desired (or what it feels is the correct position) as determined by the actual / feedback TPS mounted on the throttle.

If the ETCS-i system fails the motor disengages (there is an electronic clutch on the motor) and the throttle closes. However the cable actuated demand TPS arrangement has a small amount of mechanical failsafe built into it - you can open the throttle about 10 to 15% at a guess when the throttle pedal / cable is fully depressed (it has no effect on the throttle opening until the last 10 - 15% of travel).

I hope that makes some sense...

A few pics of the 2JZ-GTE VVTi demand sensor in this post...
http://www.toymods.org.au/forums/for...tml#post871217

this setup only uses a single butterfly

I understand that.

What I was suggesting is removing the complete throttle arrangement including demand sensor, feedback sensor, motor, throttle etc and putting that somewhere off the engine... then you could possibly fit a fully cable driven throttle possibly without the engine ECU crying about the ETCS-i throttle being missing (It wouldn't be missing...)...

It's a crap idea


Cheers
Wilbo

[mattysshop]

ahh, i see.. cheers for the info so far wilbo, i'll have a play around with it and post results if i get any!

probly won't get into removing the entire TB and swapping with something else..

as i said it's usually not a problem when driving normally.. i might just deal with it untill it's JZ time...

[mattysshop]

Revival - found that Power Amuse make a ETCS controller for the JZX100's..

they are about $300-$350 going rate for a new or near new with loom etc.. it basically allows the user to see that the throttle is only opening partially etc, and it can intercept the signal (i'm assuming something like a voltage clamp) to give 100% opening..

http://www.rhdjapan.com/power-house-...-monitor-58275

i have also found this
http://page13.auctions.yahoo.co.jp/jp/auction/r91548386
seems like a more primitive, but functional setup that allows the user to simply turn on, or off, to allow the full function of the throttle. but i can't read Japanese very well and the translators i'm using arn't that great. is anyone able to translate the description a bit better?

[George]

Wilbo, note that with ETCS-I, % of throttle opening depends on knock magnitude among other things. So the effect of poor takeoff may be partly due to poor fuel.

Overall, it's not enough to fool ECU's throttle position sensor when actually opening throttle fully. ECU would note it somehow (I don't know how yet) and enter failsafe, disabling throttle motor completely.

Also, throttle on most n/a engines is a bit oversized and one normally doesn't need it to open 100%. For example, at 100km/h with pedal to the floor I read throttle position at some 79% and MAP around 98-105 kPa (1jz-ge vvti, throttle inlet's external diameter is 70mm ).

With mechanical throttle you will usually find that at lower revs (e.g. below 2000) you have the most power at particular throttle position, that's much less than 100%, so even forcing ETCS to open more won't make acceleration faster. I think that IS200's sluggishness off the line is due to too long 1st gear and low torque. When swithed to 2nd, it would only drop revs to some 3000 where it already have a slight potential. I tried a manual altezza (6-speed), it's completely different than a/t is200 though the two cars have the same engine.

[mattysshop]

George - i kinda was hoping the ECU wouldn't do that..

fuel - always has 98RON in it, i have had the injectors cleaned, and i regularly do a de carbon, good plugs, good oils etc.. and don't get me wrong, it is smooth and suprisingly my wife can get an avg 8.9L/100km getting around town with mostly cold starts with A/C on all the time etc etc.. so i know it's quite healthy

the other day when i was playing around with it, i took it for a drive with no air intake over the radiator (was working in the general area) still ran the air filter etc.. and thats when i noticed a huge difference.. 1st and 2nd, not really much induction noise, but once it cleared approx 4200-4300rpm in second (about 75km/h) you could audiably hear the throttle open right up, almost like VTEC/VVTi-L, i mean it sounded angry like my ITB 16v 4AGE, huge intake noise.. i repeated this test over and over i could not get it to 'open up' at all in 1st gear, regardless of turning TCS off, and clicking the ETCS PWR button on the console..

i don't think the gearing is actually that bad - 2nd gear is at 6500 by 95ish km/h..

[mattysshop]

so a mate of mine just showed me these, and whilst i normally hate all the RSM, speed meters, and dancing colourful displays that 'imports' seem to have.. this seems like it may be worth while..

but the IS200 1G-FE is not listed, and nor is the IS300/GS300 VVTi 2JZ-GE, however the 1JZ and 2JZ direct injection variants are.. i am completly unfamiliar with these engines, and do not know if they are 100% fly by wire, or a combination of throttle cable + electronic assistance/resistance..

http://www.pivotracing.com/product/THF
http://www.pivotracing.com/files/199..._catalog-e.pdf

[George]

1jz-fse and 2jz-fse use etcs-i (drive by wire, not some sort of an aid), as well as some of the late 1jz-ge and 2jz-ge's. First gen of etcs-i however run cable linked pedal sensor, which may be confusing.