Author Topic: 2 wire PWM idle control (PID)  (Read 17557 times)

Offline Lizard

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2 wire PWM idle control (PID)
« on: April 19, 2010, 09:14:18 am »
I have searched the members pages, and this forum and cannot find the documentation regarding adjusting the closed loop PID idle control.

I have the car idling OK, but it is too high.
And then I cannot get it to adjust up/down or compensate for loads (ie fans or AC)

TIA

Offline Lizard

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Re: 2 wire PWM idle control (PID)
« Reply #1 on: April 19, 2010, 12:59:32 pm »
I should have noted firmware 1.0.78
V3

Offline mattias

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Re: 2 wire PWM idle control (PID)
« Reply #2 on: April 19, 2010, 04:50:42 pm »
It's quite complex, but you must look over your reference duty cycle table.
Disable ignition advance idle control while you're adjusting the IAC.

Offline Lizard

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Re: 2 wire PWM idle control (PID)
« Reply #3 on: April 19, 2010, 11:30:52 pm »
I have all ignition idle control disabled. 

Do you have a link to a manual on how to adjust it? As what you have said makes no sence to me, and I have nothing that I can find which is a reference duty cycle table in the tabs etc.

This is the only downside to VEMS over other systems that I have used. A complete lack of documentation.

Offline lugnuts

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Re: 2 wire PWM idle control (PID)
« Reply #4 on: April 19, 2010, 11:59:06 pm »
Are you using Megatune or VEMSTune?

If VEMSTune - what version number (date)?

In order to help the people to help you it is best to provide us with all of your information.

Documentation is a two way street.


Offline rob@vems.co.uk

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Re: 2 wire PWM idle control (PID)
« Reply #5 on: April 20, 2010, 01:01:58 am »
Documentation is a two way street.

True, but in this case its a two way street, that happens to be in an obscure part of a back water town, in a little visited region of a neglected country, where no maps have ever been commissioned.  Oh and GPS satellite coverage is shakey because of the high mountains and often overcast skies. ;D

Offline Lizard

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Re: 2 wire PWM idle control (PID)
« Reply #6 on: April 20, 2010, 04:33:34 am »
Last I checked V1.0.78 didn't work with vemstune :P

I thought I had posted that I was using MT 2.25 but I forgot to oops.

Offline mattias

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Re: 2 wire PWM idle control (PID)
« Reply #7 on: April 20, 2010, 06:40:46 am »
Do you have a link to a manual on how to adjust it? As what you have said makes no sence to me, and I have nothing that I can find which is a reference duty cycle table in the tabs etc.

This is the only downside to VEMS over other systems that I have used. A complete lack of documentation.
I began writing something like a guide way back, it might make it into VemsTune some day.
http://www.vems.hu/wiki/index.php?page=MembersPage%2FMattiasSandgren%2FIdleValveTuningGuide

I don't mean to dis-respect but some kind of intellect and inquisitive mind is required to learn and use these things. If you ever looked through the menus in MegaTune or VemsTune you would not have missed the dialogs that concern this and the reference dutycycle table for the IAC valve.

Screenshot of MegaTune with .ini for 1.0.78 firmware (all MT versions are 2.25, the ini for the firmware is the necessary info)

Offline Lizard

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Re: 2 wire PWM idle control (PID)
« Reply #8 on: April 20, 2010, 08:18:53 am »
Rob,
no offence taken.
However in my setup this selection is greyed out. Which is why I hadn't seen it.

Will take a closer look tomorrow

Offline rob@vems.co.uk

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Re: 2 wire PWM idle control (PID)
« Reply #9 on: April 20, 2010, 02:34:30 pm »
No offence at all - I was attempting to make light of the documentation - apparently it is all out there, but no one can find it!

Offline Lizard

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Re: 2 wire PWM idle control (PID)
« Reply #10 on: April 21, 2010, 12:10:57 pm »
Hey Rob,

It might be nice to do something like they did for the MS manual.

http://www.megamanual.com/mtabcon.htm

That is it, and it has a link to everything one could want to ask, in great detail.

For VEMS we have to go through member pages. Which none of them tell us what topics they cover, or if it is just a blurb about their particular install.
You can also try to find them via google or another search engine, but there are simply not enough tags on the pages for google to be able to pick them up/out.

But just doing a simple menu right off the vems.hu webpage. And in that link something like the MS page, so if one wants to look up PWM idle valves they click on that and it shows all the members pages which could have information on it.

And I do tend to be a very inquisitive, and intellectual person, or so I am told. :P But even the most brilliant minds over look things right in front of them from time to time.
And looking at the memberpages linked, I will be going over it with MT up and looking at it.
But right now I can say that even after reading through the page, I have no clue what mdi is.
Nor have I any clue what the different setting boxes are for in the menus. Some of it I have figured out. But there are a fair amount that is simply 1 or two letters which are obviously abb. but with no link as to what they actually are abb, for.

Offline rob@vems.co.uk

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Re: 2 wire PWM idle control (PID)
« Reply #11 on: April 22, 2010, 01:01:16 am »

Offline Lizard

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Re: 2 wire PWM idle control (PID)
« Reply #12 on: April 22, 2010, 03:48:02 am »
Rob,

I had read over those many times.
There is in my opinion much missing from them.

However from the prior link provided I have deduced the information that I needed.
The problem is that this is my friends car that I have to work on when he is here. (lives in HK)

I just managed to get back to it today and got all the system set up.

But have found a snag,
I was running the PWM valve off injector fet 8 (i7) and cofirmed a switched +12v to the other pin.
But the valve is not getting any signal at all.
I also tried econo 36 pin 6 which is injfet 7 (i6) and still I got no signal to the valve.
I ohmed out the harness and it is fine.

What setting might I be missing to prevent either of these from controlling it?

And I am afraid I was mistaken on the code. We are running 1.0.73final as there was a glitch in 1.0.78 when we were starting.

In idle settings,
control type pwm/stepper
IAC hardware setup
type pwm
solinoid channel injfet
solinoid channel # i6 (pin 6 econo 36)
dual solinoid disabled.

If someone could direct me to the next step or what I am missing it would help.

Offline lugnuts

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Re: 2 wire PWM idle control (PID)
« Reply #13 on: April 22, 2010, 08:20:52 am »
I use "6" instead of "i6" for the outputs.

I only use the "i" to test outputs for ON?OFF on the workbench.

Offline Lizard

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Re: 2 wire PWM idle control (PID)
« Reply #14 on: April 22, 2010, 08:56:49 am »
the options only give me i6, not just 6.

Do you use a different channel?