Enraged your a GENIUS!!!! i think gutting the stocker and piping a ford on there is a perfect simple way around using the toyota 6 wire, a ford is the way to go thank you!
Megasquirt3+MS3X
- Thread starter KTM530
- Start date
If you need one I have both a ford and a BMW idle valve just sitting in my basement from when I was messing with the megasquirt. Pay the shipping and they are yours.
I was planning to remote mount mine under the intake manifold. The 2 wire Fords work better with the AEM v1, and they are cheap.
You can run the stock ISCV. You really don't have to rewire it either. It works perfectly. You don't connect the two middle wires to anything. Just run the 4 outside ones. It works. Look at post 4 in my thread. http://www.supramania.com/forums/showthread.php?169725-1987-Supra-Turbo-Build-*Running-Megasquirt-2-Extra-with-bluetooth-and-android*
The idle valve will not operate without the 2 middle wires which are power. Power is applied to those and then grounded in the right sequence to make the valve open or closed.
It is also always commanded full open upon shut down. So basically you tuned your idle with a huge air leak.
It is also always commanded full open upon shut down. So basically you tuned your idle with a huge air leak.
The power is supplied via megasquirt. Megasquirt can drive a bipolar stepper motor IAC, but not a unipolar IAC. The way the stock ECU drove it was with by grounding each coil like you said. That is the unipolar way of driving it. That's why it needed the 12v power. Megasquirt supplies the power directly and switches polarity to the coils to actuate the valve. I did a test with it and cycled it all the way through its 125 steps from open to closed and back again. Speedfreak426 did the same thing on his 1977 celica with a 7m swap. It works. I'm just trying to save you guys unnecessary time and money.
Pyro15D;1902474 said:
I have been looking into using the idle motor in the stock configuration for many months now. This was my first clue that it could be done. It is for a 5m plug-and-play kit that DIY sells. It uses the same 6 wire idle valve as a 7m, 1jz, 2jz. Half way down they briefly explain the setup. For MS2.
http://www.diyautotune.com/diypnp/apps/n52/usdm-toy-supra-8384-5mge-mt.html
Today I got it working with a stimulator, and MS3+MS3X. I can get it to move to any position between 1 and 230 steeps, it runs to the home position at power on, reacts to coolant based idle up, moves to a cranking postion.
I gotta ask, why do you say MS cant run a unipolar stepper motor?
"it cant be done with MS" really means "I couldn't figure out how to make it work"
The reason why megasquirt can't run a unipolar motor is because unipolar means the coils inside the motor itself are powered with only one polarity. That's why the two center red and black wires are connected to 12v on the stock ecu. To make the stepper motor "step" through its range of motion, the ecu would just sequentially ground the other 4 wires, energizing the respective coil along the way. I can only assume that unipolar was a more primitive way of controlling stepper motors, and nowadays, the technology is there to energize each coil with both polarities. Now that being said, there is no way for megasquirt to run unipolar. The stepper motor driver chip that is built onto the ms2 board is a bipolar motor driver. Any unipolar stepper can be made to work with a bipolar motor driver, but not the other way around. The rule of thumb I always thought was if it has 3 or 4 wires, it is most likely a bipolar stepper. If it has 4 or up, it is most likely unipolar. I might have gotten too deep into this and just made it confusing but I do have a habit of getting ahead of myself lol!
Pyro15D;1902474 said:
i just started installing the MS3+ms3x today, i have not been motivated since winter break began and now on the last day of break I decide to start the MS3 install. I mounted the bosch 2 wire and mocked up the harness, and now i see i could have stuck with the stock unit...... oh well 2 wires are easier than 6 anyways. I should have taken a look here before starting.
here you guys go
http://www.supramania.com/forums/sh...ta-IAC-and-stepper-design-)&highlight=bipolar
can't believe I did that work nearly 7 years ago already. Back then, this was based on Tec3 but works with any EMS that supports bipolar (which is most) stepper control.
the important part will be the .25 seconds per step rate. To fast, fry coils, to slow, won't move.
http://www.supramania.com/forums/sh...ta-IAC-and-stepper-design-)&highlight=bipolar
can't believe I did that work nearly 7 years ago already. Back then, this was based on Tec3 but works with any EMS that supports bipolar (which is most) stepper control.
the important part will be the .25 seconds per step rate. To fast, fry coils, to slow, won't move.
DustinS;1935072 said:
I am a little reluctant to share to much of my setup at this point because it is totally untested at this time. I will say that all the mods inside the box are per the manual.
figgie;1935223 said:
Hmmm, when i was doing my testing i found that the valve would not move with a signal any faster than 5ms between steps. It seemed to work great at 10-15ms. I Kept moving the valve at these settings for several mins without the valve generating any noticeable heat.
At .25 seconds per step on a valve that has 200+ steps, it would take almost a minute to open or close the valve. Did you mean 25ms?
EDIT: then again I did not swich the configuration of the valve. I may be comparing apples to oarnges.
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mkiiichip;1935292 said:
The windings are to small to generate heat that you will be able to feel before the windings give the ghost up.
.25 seconds = 250ms which is more than 10-15ms or put another way, a quarter of a second on a bipolar design. The stock design is really quick (if you look at the post, as jetjock alluded to. It is getting fed signals all the time from the TCCS). That is a 3p question though.
You are essentially feeding two coils at a time meaning higher current. No different than a higher dwell time in an ignition coil requiring more time to get the mag field at the right mH.