2JZ IAC Stepper motor issue

[fonz87]

Hello

Is there an issue with EMU and Idle Air Control on the 2JZGTE? we have been having some issues where the 2JZ is idle hunting and have trouble starting at start up.

Also have some RPM drops and acting up when coming off from first gear under 1500.

Was wondering if there are some known issues or how the IAC Setting should be set up.

I would be happy to provide the Tune I have to help with issue.

Thanks

[Jadzwin]

Did you connect the stepper motor like in this documetn ?

https://dl.dropboxusercontent.com/u/286 ... 0motor.pdf

[fonz87]

Wiring is not an issue for the IAC,

Just need to know what the settings should be?

My car would bounce RPMs and I can hear my IAC turn off and turn on and i m rolling off First gear

[Jadzwin]

Please include log file

[Kisielisodd]

Try

frequency 100hz
stepper steps rage 150 .... or 100 I don't remember

[fonz87]

I will try to post logs and screen shots of settings I have in the system.

Thanks

[WHPZach]

Hello

Is there an issue with EMU and Idle Air Control on the 2JZGTE? we have been having some issues where the 2JZ is idle hunting and have trouble starting at start up.

Also have some RPM drops and acting up when coming off from first gear under 1500.

Was wondering if there are some known issues or how the IAC Setting should be set up.

I would be happy to provide the Tune I have to help with issue.

Thanks

Your car has just a rough startup tune. Your IACV settings should all be correct, your car just needs tuning. Also, the IACV plays very little part in starting your car, your cranking pulsewidth for the fuel injectors is the biggest factor there.

[fonz87]

Hello

Is there an issue with EMU and Idle Air Control on the 2JZGTE? we have been having some issues where the 2JZ is idle hunting and have trouble starting at start up.

Also have some RPM drops and acting up when coming off from first gear under 1500.

Was wondering if there are some known issues or how the IAC Setting should be set up.

I would be happy to provide the Tune I have to help with issue.

Thanks

Your car has just a rough startup tune. Your IACV settings should all be correct, your car just needs tuning. Also, the IACV plays very little part in starting your car, your cranking pulsewidth for the fuel injectors is the biggest factor there.

ZACH,

we re did my map tune and it starts up no problem and we been driving it and boosting but this issue with the roll off from first gear has us confused. I don't have the funds to get it tuned by SP at the moment so we are trying to figure out what the problem is on our own. I dont seem to be the only one having the same issue, KORNFUEL is also having the same issue as well.

I tried attaching the log in this post but the log is too big of a file, I can email you the log JADWIN

Thanks

[fonz87]

Try

frequency 100hz
stepper steps rage 150 .... or 100 I don't remember

Issue is fixed from a help of a friend

Kisielisodd you were on the right track about the frequency and Stepper Range, those numbers needed to be adjusted and fixed the issue.

[fonz87]

Can someone explain to me what the frequency ranges should be on the 2JZGTE Single Turbo motor should be?

How is the frequency determined?

Thanks

[Jadzwin]

What frequency do you mean ?

[fonz87]

for Idle motor setup.

there is a frequency setup and would like to know what the frequency should be and how is that determined and what the stepper steps range should be and how is that determined.

For Example, for the TPS, there is screen where it tells me what the % is at "Zero" throttle and what the Percentage is when I m Full Throttle and adjust my TPS by that but I m not sure or understanding how Frequency Setup is set and stepper step range is setup, what the values should be and how are those numbers determine



thanks

[WHPZach]

The frequency and step range are determined by bench testing the IACV valve itself. All 2JZ valves are the same, so you shouldn't need to change anything in this menu aside from maybe adding some duty cycle for the "afterstart increase" to help bump the idle on a cold motor. What you will need to do is ensure that your VE table is nice and smooth and that your other idle tables are adjusted correctly. Again, the settings I'm posting right now are the correct settings for the 2JZ IACV. If you're having an idle issue it's extremely unlikely that it has anything to do with these settings. You should first ensure that the VE table is correct, that you have a nice timing "pocket" in your ignition timing table, that the car idles at the appropriate RPM as it warms up (adjust your duty cycle versus engine coolant temp table for that) and then once all that's done, you can enable PID control and ensure that the PID function is working correctly. Again, dialing in PID control isn't something that a beginner will be able to jump right in and sort out, this is why it's recommended that you take the car to somebody that's familiar with tuning and can get it right the first time. If you make changes without having a full understanding of how the system works, you'll just end up making more work for somebody to sort out later. You can spend hours and hours chasing your tail if you don't follow the correct steps.

[fonz87]

Thanks Zach,

We lowered my Frequency range and raised my stepper motor higher and it helped with my weird idle bounce at 1st gear roll off, but it seems to act up still, here and there when it's warmed up, I'm guessing the Table will need adjustment and well as the After start "RPM". I will have to get my car tuned by Larry.


EDIT - just saw your settings, i will give them a try and see how my car reacts. Thanks!!

Thanks