MS3x for Lexus 3uz

[Hiluxfan]

Hello everyone.

I am new to the MegaSquirt family.

My plan is to fit a unit to the Lexus 3uz motor. I am thinking of the MS3X.

I have read all I can find so far and pretty confident.
My only concern is the VVTI. Can this be managed by MS3x and how?

Many thanks.

[jsmcortina]

VVT is supported on some engines. It depends on how the lexus 3uz handles it.

http://www.msextra.com/doc/ms3/vvt.html

James

[Hiluxfan]

Ok Ive done a bit more searching and came across this:

http://www.msextra.com/doc/ms3/vvt.html

It seems that you need the 1.1 alpha code. Only that code supports VVTI.

Does anyone have experiance with this?

I really dont want to buy and assemble everything without being sure if it can be done.

Many thanks

[Hiluxfan]

Thanks James
I only now see that you have posted the same link.
I believe the 3uz would be similar to the 2jz VVTI but only X 2 cams.
See:
viewtopic.php?f=125&t=41606&hilit=vvti

[Hiluxfan]

Hi Guys
I am slowly but surely building my first MS3X. It has really been fun and I have learnt a lot.
I am now at the point where I have to do the configuration of the IAC valve. I’ve done a lot of searching but cannot find how to do this for the Toyota (Lexus) 3UZ.

The UZ family of engines uses a six wire stepper motor valve.
This is what I was able to find on it.

IAC Valve check and wiring.gif (44.11 KiB) Viewed 796 times

Has anyone been able to addapt the MS3X to opperate with this?

Thanks in advance

[SymTech Laboratories]

The stepper motor driver signals are brought out through the main connector, not the MS3X. The stepper motor driver is meant to drive bipolar stepper motors, but it sounds like your IAC uses a unipolar stepper motor. You can often use unipolar stepper motors as bipolar stepper motors, though. In this case you would probably leave B1 and B2 disconnected, then use the other four wires as if they were from a bipolar stepper motor.

[Matt Cramer]

In this case you would probably leave B1 and B2 disconnected, then use the other four wires as if they were from a bipolar stepper motor.

You may not even need to disconnect B1 and B2. We actually managed to get the bipolar driver to work with a unipolar stepper with the power supply wire hooked up on a 5MGE motor. We just set it to "moving only" mode and got it dialed in.

[SymTech Laboratories]

You may not even need to disconnect B1 and B2. We actually managed to get the bipolar driver to work with a unipolar stepper with the power supply wire hooked up on a 5MGE motor. We just set it to "moving only" mode and got it dialed in.

That might be best. The motor will be driven like a bipolar stepper motor (more, but unnecessary torque) if B1 and B2 are disconnected, but the driver functions more like a unipolar stepper motor driver with B1 and B2 connected.

[Hiluxfan]

Thanks for the replies guys!
I am not that clever with all the electronic stuff (yet).
If I understand correctly I have to set up the MS3 main board for the 4 wire stepper motor

(from the manual)
"i)Stepper Idle Valve: If using a 4 wired idle valve (or using as two spare outputs) then solder wires from:
a) JS0 to IAC1A
b) JS1 to IAC1B
c) JS2 to IAC2A
d) JS3 to IAC2B"

And then also connect B1 and B2 to +12V.

[SymTech Laboratories]

That's correct, but also be sure to connect JS9 to S12C.

[Hiluxfan]

Thanks for all the help guys!

I didnt get a chance to play with my MS for some time now.
The IAC is now working on the bench with the Stims.

My next question is related to the VVTI.
At the moment I am just trying to set it up for VVTI on/of.
So far I've managed to get VVTI1 working but no luck with the second one.
Ive tried different outputs such as VVT2, NOs1, NOs2 and boost.
Do I need a seperate input for VVTI2? Ive tried PT4 but I suppose it needs to be connected to somewhere on the Stim.

The manual does not give a lot of info and I cannot find too much here.

Please help!

[jsmcortina]

Post your MSQ, it is difficult to answer your question without seeing your exact settings.

James

[Hiluxfan]

Tanks James
Attached is my MSQ
This is still "a work in progress" and so far only used for bench testing.

2012-11-22_23.40.29.msq

(160.4 KiB) Downloaded 26 times

[jsmcortina]

I'm not actually sure if on/off is supported with more than one VVT valve, it doesn't really make a lot of sense - you need to use the closed loop true position system instead.

EDIT: I double checked and this is correct. On/off only works on a single output. I've updated the ini file for a future release so that the other cams will be greyed out in this case.

James

[Hiluxfan]

Thanks a lot James.
So, if I want to run on/off VVT on the engine I have to connect the one output to both solenoid valves.
I wanted to test closed loop next in any case.
Will give it a go!