Author Topic: Problem with idle output  (Read 5796 times)

Offline PIC

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Problem with idle output
« on: July 26, 2011, 12:35:47 pm »
I have a problem with getting idle to work. The car is idling at ~700 rpm. If i remove the connector from idle solenoid nothing changes. I have tryed to set the idle to 600 rpm and 2000 rpm but it has no effect. If i connect the idle solenoid directly to +12v the engine rpm goes up to ~2500. So, the solenoid must work. When i connect 21W light bulb to idle valve connector then the light gows very low intensity. When i open Vemstune at Outputs > Assign Output Channel, turn test mode on and then switch the idle output on and off, then the light works ok.

The car is Audi S2 with ABY engine.
Firmware is 1.1.88

Current config file is here: http://www.mediafire.com/?7tuhkgjvn09tocc

Offline Sambas

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Re: Problem with idle output
« Reply #1 on: July 26, 2011, 01:10:09 pm »
in idle hw settings max pwm duty allowed 12% limits the movement very low.
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Offline mattias

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Re: Problem with idle output
« Reply #2 on: July 26, 2011, 01:42:15 pm »
Begin by doing this :
- Set Max/min PWM to 100 and 0 %
- Disable PID (set all three values to 0, or integral increase/decrease to 0).
- Create a reference duty cycle curve that maintains 200-300 rpm above the "idle target rpm" (tune while looking at all gauge for IAC).
- Now set max/min PWM to values that correspond to just above/below the ref duty cycle at all coolant temps.
- Enable PID again. Will need some tuning.

At the moment you're limiting the opening to 12% - which is probably way out of the operating range of the valve = it's closed all the time.
The point is to let the PID regulation lower the rpm to to idle target rpm down from the reference duty cycle value.

Offline AVP

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Re: Problem with idle output
« Reply #3 on: July 26, 2011, 07:31:19 pm »
if you are using the OEM idle valve, it also has this specific reaction(from what i have gathered by other users): if set below 29% DC, it tends to reopen and if set even lower, it opens more. So the fully closed position of the valve is around 30% DC give or take.Also your DC curve is all over the place..

as mattias advised, this is the ideal method of setting up idle and i think it should be made a sticky!

« Last Edit: July 26, 2011, 07:32:58 pm by AVP »

Offline PIC

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Re: Problem with idle output
« Reply #4 on: July 27, 2011, 09:36:15 pm »
Thank you! I will test it out on this weekend.