Electronics help with TPS circuit.

[sideshow]

i fitted a spd adjusting device to my 1uz auto ecu and can adjust when the auto ecu changes gears

this is done without touching gear sifter

if i slow the speed signal to the ecu i can change gears at 6000 6500 or just hit rev limiter then change gear but i you slow it too far u have to back off when it hits rev imiter to change gear

so if your car is in std trim and std ecu and on full throttle does it hit redline when it changes gears??

with my spd adjusters i can change the signal by a minute amount

one day i adjusted it too far and it started changing gears on redline so i then sped up the signal

not sure if this will help but if you have similar sympton maybe speeding up the speed signal by a tiny amount might make it change gears say 300 to 500 rpm less

i have it hooked up to the main spd signal to ecu from gbox not the one from dash

[BMWTurbo]

Thanks for the info Injenious way to trick the 8's. I used to play with the kickdown cable lenght on them

This is a slightly different issue I think though in that it's an ECU induced lower rev limit. I can make the engine rev limit at say 4000rpm when you stomp on the throttle and it hits the kick down switch, but you hold it down. I can also rev past 6000rpm if you hold it in gear manually, so it's not fault in the limit as such.

If on the other hand you stomp on the throttle and then back it off so the KD engages then dissengages and you roughly hold 80-85% throttle it will pull through the gears and rev out like it should.

I had the same thing happen at 90kph on the highway, it dropped back to second and then pulled for a little bit and then hit limiter...

AT first I thought it might have been boost cut, but it doesn't flick the engine check light on and just bounces off the limiter unlike the hard Boostcut where it stops pretty much. I've also fitted a FCD so I know it won't hit boostcut now, but it still does this weird low rev limit on a hard kick down.

[PlacentaJuan]

the kickdown switch has no relation to this problem of the rev limiter activating to early.

it doesnt happen on standard aristos either.

with the tps output clamped to a certain voltage (via a fcd) the engines 'natural' rev limiter will still activate like normal.

the relation that the tps has with the auto gear changes makes me thing that if i was using a manual this wouldnt happen also.

i assume that this issue may be solved with an aftermarket ecu (piggyback coz i have an automatic), but until then my most recent idea was to build a jaycar kit that switches a relay depending on frequency (and therefor can be hooked up to the tacho to switch at a certain rpm) and use it to switch in the fcd circuit.

i will update if this works.

[BMWTurbo]

If the std ARisto doesn't do this I'm wondering if it's a wiring issue. I know there are a heap of traction wires in the loom and also other sensor wires.

Is the ECU expecting a reference feed of speed signal back like the soarer does?

Unfortunately I don't have a comprehensive wiring diagram for the aristo to trace out all the wires. I was only going by what I managed to trace in the vehicle loom.

I doubt it's to do with th rate of RPM increase of VSS increase either because my car won't break traction in the dry so it can't be a function of this.

[sideshow]

i know if the wiring is not correct some v8s have a permanant rev limit of 3800

it brings up code 56 and alot of people have found htis code and you have to do something to the wiring to fix the problem


i quickly read thru the thread cant be fucked tryin to understand it

i havnt seen or felt this prob on any toyota so not sure what the whole thing is about

anyway have you checked for codes

most toyotas have 2 spd signals

one is main the other is backup

if one is missing it takes the other one

main one is the one thast comes from gobx not the speed sensor from back of dash

if it only does it on cars that have a conversion done then its probably a wiring issue

even a different diff ratio might even cause spd probs

i have done afew 2jzs and since i hate driving owners cars some cars i just would not hop in i dont feel how they change gears

but no one has complained about any probs

anyway good luck with it im off to chill out for weekend

[ProjectSleeper]

Sideshow,

After you managed to fix my cruise control issue so quickly and easily after everyone else was left scratching their heads or didn't have time to look at it, I am happy to let you use my car as a guinea pig...

I am happy to bring my car to you and you can suss it out if it is just a simple problem with the wiring or whatwever. Once you can work out "what" is happening, you can probably work out "how" to fix it..

Then once you know that - others can bring them to you to fix them..

I can probably arrange a dyno and operator to make it heaps easier....

[sideshow]

i dont get much tiome off these days to look at things

way to booked out these days

only do special orders for a select few these days

im starting to enjoy gettin home at 5 pm


i would go back and complain to person who woired it first and complain hehehehe

good work is hard to find these days

and im sick of fixing other people fuk ups so i just shaft them if they want it redone heheheheheheheehehehe

[ProjectSleeper]

No probs,
I fully understand where you are coming from..

I am happy enough with mine the way it is, was just offering to supply you an example to work on ( as per my PM to you, I am more than happy to pay for your time) - then you can work out with the others if you want to fix them..

No point complaining to the original person, he is not sure why it is doing it either, and he too is uber busy latey, so I hold no grudges...

But if ya too busy, then that's kewl. I can live with it the way it is and of I need to kick it right down, I just use the Selector (which is less stress on the clutches when changing from 1st to 2nd anyway).

Enjoy ya weekend.

[PlacentaJuan]

yea i know i have trouble explaining things, specially after a few too many whiskeys...

3800 sounds about where the problem occours also (even though i dont have a tacho working yet, not that it woudl give me an accurate reading anyway)

also i have been to a few dyno days, the last one was about a week ago and i wasnt using the fcd clamping circuit and the car had no problem revving at all.

its like if you feed on the throttle there is no problem, but if i just plant my foot down it will hit the false rev limiter.

i will let you guys know if the rpm switch tihng works.

i was driving around for a while with a switch to select between true tps signal and a clamped tps signal and it worked really well, until i forgot to 'unclamp' it and lost all kickdown!

hopefully this jaycar thing will switch it automatically.

[Mos]

This is a slightly different issue I think though in that it's an ECU induced lower rev limit. I can make the engine rev limit at say 4000rpm when you stomp on the throttle and it hits the kick down switch, but you hold it down. I can also rev past 6000rpm if you hold it in gear manually, so it's not fault in the limit as such.

If on the other hand you stomp on the throttle and then back it off so the KD engages then dissengages and you roughly hold 80-85% throttle it will pull through the gears and rev out like it should.

I had the same thing happen at 90kph on the highway, it dropped back to second and then pulled for a little bit and then hit limiter...

BMWTurbo, how are you determining this rpm value?

I still maintain this is the auto changing gears (perhaps more than one) and the engine hitting the true rev limit - I did not experience anything other than this when driving mine - this was most evident when the gas was mashed on the dyno - the transmission tried to shift at 120km/h (in 2) from 2nd to 1st and instantly hit the rev limiter, gentler feeding of the throttle didn't shift gears and allowed full power output. (Jason, I'm hearing what you're saying but the observations differ from my observation of driving exactly the same car).

This is a theory that is incredible easy to test out - unplug the solenoid connector off the auto - that way the ECU can't shift down and if I'm correct it shouldn't rev limit until 6800 or so (determined as the approximate rev limit by slow acceleration on low throttle opening in L).


In terms of primary auto speed sensor, SP2, the three cars in question (Jason's, Jesse's and Adam's) use the MX83 extension housing and output shaft with the MX83 speed sensors (ABS sensor and vehicle speed sensor). The original aristo SP2 rotor and speed sensor is not fitted - this sensor can be fitted by machining the housing and the rotor components to add the third sensor to the extension housing - Jason, if you still have all the original parts off the aristo extension housing talk to Jason Myers as he does this mod (the looming is still there untouched). Personally I don't think it will change anything, but you can install it for the sake of removing variables if you wish.

Jim, BMWTurbo, what extension housing and speed sensors are your experiences running?

Out of the three cars, two half cuts originally had kickdown switches, one did not. Given the reported issue happens on all three it suggests this is not a variable (in agreement with Jesse's findings).
Other than the SP2 speed sensor, the kickdown switches, the fuel pump ecu, and the entire ABS/TRC mess, the three cars are wired up exactly as the half cut was. (Thank you for the kind words Jim ).

In terms of error codes, Jason's original TPS was open circuit and the ECU did not throw an error code...

If standard Aristos don't do it, find out what else is different. Do standard aristos have individual dumps with 3 or 3.5 inch exhausts? Do they have bleed valves and FCDs and rising rate fuel pressure regs? Does an aristo weigh 1400kg?

Mos.

[ProjectSleeper]

Mos,
I don't have any of the old Trans bits, they went with the old motor to a bloke in Canberra.

It may just be your transmission then...

I had my Auto serviced today (been about 13 mths since it was rebuilt) and according to the Trans specialist, there were quite a few differences between the trans in your old car Mos vs mine. The clutches were different for a start and (whilst I don't fully understand the workings of an Auto) the parts they ordered for his (based on mine being there previously) were completely different...

(he even double checked today to see if he had made an error)

I can only go on the way Adam was driving (thrashing) it when he took me for a drive in it - I personally did not drive it. However, when we were side by side at about 30km/h and just idling along and we both nailed it - neither of us kicked down and the steel wheels in his turbos actually took heaps longer to spool and I easily got about 1 to 1.5 car lengths before he came on boost fully.. Hence I know that he didn't kick down...

As I have said, if it is an easy fix, - happy to do it, but if it's a hassle, I can live with it how it is.....

[sideshow]

i was goin to ask that next mos

i do know that most people modify the back of the gbox to suit the cressida

and to get the factory sensors working so the abs etc work ok means you stuff up the sensors that goto the gbox

this could be the problem

7ms have 3 wire sensor and 1j and 2js have a 2 wire sensor

and they also have different number of pulses

problem is to get these signals working back to std state is not cheap due to parts

being 330 bucks for an analog signal adjuster

did u wire them up mos ???

sorry if i insulted anyone


ive learnt from doin too many shit jobs from last year that this year i dont care about anyone

im sticking to doin big jobs and good paying jobs

in other words i have to be a **** heheheheheheheheheeheheh

[Mos]

Mos,
I don't have any of the old Trans bits, they went with the old motor to a bloke in Canberra.

I still have the SP2 rotor and sensor... the rest involves your MX83 extension housing and MX83 speed sensors.

I had my Auto serviced today (been about 13 mths since it was rebuilt) and according to the Trans specialist, there were quite a few differences between the trans in your old car Mos vs mine. The clutches were different for a start and (whilst I don't fully understand the workings of an Auto) the parts they ordered for his (based on mine being there previously) were completely different...
(he even double checked today to see if he had made an error)

Yeah, Adam mentioned it was a bit of an abortion. I was told the clutch packs were the Aristo ones, the planetaries were the cressida ones (not that it really matters now). I had all the bits he pulled out, but it is a bit weird that he would've done the same job two different ways.. oh well..

I can only go on the way Adam was driving (thrashing) it when he took me for a drive in it - I personally did not drive it. However, when we were side by side at about 30km/h and just idling along and we both nailed it - neither of us kicked down and the steel wheels in his turbos actually took heaps longer to spool and I easily got about 1 to 1.5 car lengths before he came on boost fully.. Hence I know that he didn't kick down...

Adam thrashing it? surely you jest

As I have said, if it is an easy fix, - happy to do it, but if it's a hassle, I can live with it how it is.....

There's no guarantee it will fix anything, but adding the SP2 sensor returns the combo to factory spec. Jason Myers can do all the machining provided you supply your extension housing and rotors off the output shaft.
Mechanically it's fiddly, but it's reasonably easy to remove the extension housing while it's in the car. Electrically you plug the sensor in using the plug that's still there.

i do know that most people modify the back of the gbox to suit the cressida
and to get the factory sensors working so the abs etc work ok means you stuff up the sensors that goto the gbox
this could be the problem

7ms have 3 wire sensor and 1j and 2js have a 2 wire sensor
and they also have different number of pulses
problem is to get these signals working back to std state is not cheap due to parts
did u wire them up mos ???

The extension housing currently has the ABS sensor (3 wire, 32ppr) and the standard vehicle speed sensor.
The SP2 signal (in this case 4 ppr 2 wire sensor) is not hooked up. As stated above, adding it is reasonably easy, however most people choose not to spend the extra as in theory the transmission will shift off the vehicle speed sensor. The cost of modifying the components to add the SP2 signal is in the vicinity of $200-300 if you do the removal and fitting yourself.

We do this mod on single turbo 1JZs as the 1JZ extension housing only has the SP2 sensor (12ppr iirc) and no vehicle speed sensors. We use the MX83 extension housing and add the SP2 sensor.

Mos.

[sideshow]

i have an electronic device that can take the 32pulse 3 wire signal and make it a 4 pulse 2 wire signal

but its 330 bucks just for the unit

[PlacentaJuan]

btw mos, just remembered, when i put in the smallest restrictor plate in my exhaust, which limits boost to nearly stock (12psi) it doesn't hit the cut as early in the rev range, sometimes doesn't hit it at all!


sorry i didn't remember this at all, but the exhaust and increase in boost probably have something to do with it.....