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Idle question

Posted: Sat May 12, 2012 6:09 pm
by TurboTim2
So I have some kind of big bulky bosch 2 wire IAC. I had it running on the expansion side of my box but I was looking as saw that it was only a medium current driver so I decided to move it over to the PWM idle valve wire. Well now the vehicle doesnt shut off unless I unplug my IAC. I dont have my IAC to turn off when I shut the key. It powers down when the fuel pump and main relay shut off. It didnt seem to be pulsing anyways when I was using it either. Is Fidle on the main board or expansion and what connection should I be using to get it to work?

Re: Idle question

Posted: Sat May 12, 2012 7:32 pm
by TurboTim2
Also how do I let MS know that I have my AC on and does it need it to pull whatever wire to ground or 12v?

Re: Idle question

Posted: Sat May 12, 2012 11:25 pm
by kizzoalfa
If you have MS3x, use the Idle output. Also make sure you have the antiparalel diode for your valve. The built in flyback circuit of the MS3x does not works with the Bosch 2 wire solenoid since the clamping voltage is high and due to to high flyback energy the effective driving power for the motor is lower. Add a diode from Idle to +12V (Idle should be the anode) - you can put it to your valve harness. You have idle when you disconnect the motor is because the Bosch valve is normally open (you can look inside) and when you apply like 30% PWM than it just closing and probably fully open at 80 % PWM.

You can connect the valve and try HW test in the output test section of TS: first set the frequency (around 200Hz) and than determine the closing and maximum opening points. (Without the diode it will not work.)

Re: Idle question

Posted: Sun May 13, 2012 6:13 am
by TurboTim2
So would I have damaged my valve if I hooked it up without a diode? So when you say the idle output, do you mean the standard one that comes on non expanded ms or the medium current driver one on the MSx boards, just want to make sure I am using right one. Last question, so I hook the diode so current can flow from power to ground right? And I would want it on power side or ground?

Re: Idle question

Posted: Sun May 13, 2012 10:04 am
by TurboTim2
kizzoalfa wrote:If you have MS3x, use the Idle output. Also make sure you have the antiparalel diode for your valve. The built in flyback circuit of the MS3x does not works with the Bosch 2 wire solenoid since the clamping voltage is high and due to to high flyback energy the effective driving power for the motor is lower. Add a diode from Idle to +12V (Idle should be the anode) - you can put it to your valve harness. You have idle when you disconnect the motor is because the Bosch valve is normally open (you can look inside) and when you apply like 30% PWM than it just closing and probably fully open at 80 % PWM.

You can connect the valve and try HW test in the output test section of TS: first set the frequency (around 200Hz) and than determine the closing and maximum opening points. (Without the diode it will not work.)
Okay reread your post on a computer and not my cell phone and did some research on the anode end. I got this figured out. Will see if I can find something on the idle up for AC though.....