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How to test PWM IAC mod on stim?

Posted: Mon Jan 16, 2012 9:41 am
by akeboshi
hello,
I just installed the pwm iac mod on my ms2 v3.0 pcb running on b&g 2.8900 code and I was wondering how to tell if I installed the mod correctly? I assumed that when I built it and configured it in TS that the IDL light on the stim would light up but it doesnt light up. Can somebody please enlighten me? Im pretty sure iI built it right but I can test it on the actual engine for a few more months.

Re: How to test PWM IAC mod on stim?

Posted: Mon Jan 16, 2012 12:51 pm
by Matt Cramer
It can be tested as an on/off, or you can see if the brightness of the LED changes with the CLT adjustment.

Re: How to test PWM IAC mod on stim?

Posted: Wed Feb 29, 2012 3:50 am
by kieranl
Matt,

Im having a similar problem, except my LED is staying on.

Ive modded for the Ford Valve Following these steps:

For PWM Idle Valve Users Only
Note - if you are using a PWM idle valve (Ford or Bosch 2 wire valve - see this link for more information), these valves can not be operated with a relay. As a result, they need a higher capacity transistor installed.

DO NOT install Q4 for use with PWM idle valves - it cannot handle the current directly for PWM idle valves. ('On/Off' type idle valves used with a relay are fine with the default Q4.)

Instead, for a PWM idle valve, use a TIP120/121/122 transistor (such as Digi-Key 497-2539-5-ND, 74¢ ea.) mounted on either the heat sink (if you have a spare spot) or the case. You should use a mica insulator (4724K-ND, 93¢) with heat sink grease as well. Run wires to the Q4 connections as shown below:

Do not install Q20, do not install D8, and jumper R39 as well. You will also have to put a 1N4001 diode across the PWM Idle valve itself - the banded end goes to the 12 Volt supply, the non-banded end goes to the lead that goes to MegaSquirt® (this diode is for flyback purposes on the idle valve).


I will also be running Ford TFI also so have followed the steps for this modification also.

I have a V3.0 board with MS-II

When the computer is hooked up to Tuner Studio, all values and pots respond accordingly.

I have changed the idle Control to
PWM Warmup
PWM Frequency is at 320
Start Value 100

I have then set in the PWM Idle Duty Cycle starting at 0% at temps running through to 100%, but then have also tried running this from 100% when cold to 0% when hot.
Ive seen you mention about turning it on and off, but can't seem to find where to do that.

With the led staying on, is this an indication if wired something incorrectly?

Thanks,
Kieran

Re: How to test PWM IAC mod on stim?

Posted: Wed Feb 29, 2012 4:22 am
by kieranl
Please ignore, problem sorted :D