Ideal Idle Air Duty Cycle with warm engine and zero load

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Ideal Idle Air Duty Cycle with warm engine and zero load

Unread postby 89FiveOh » Thu Jan 11, 2018 5:33 pm

First timer here. Is there an ideal duty cycle for the IAC for warm engine idle with no load? Trying to dial in idle mechanically using BE with a QH. Basically, trying to set the throttle blade set screw for minimal idle without computer help. I would think logging the duty cycle of the IAC would point me in the direction the throttle blade needed to go in order to allow the IAC to handle any extra air/load as needed.
Am I correct in thinking the higher the duty cycle at idle with no load would indicate that the throttle blade is closed too much and a lower duty cycle would mean the throttle body blade was open too much? My timing at idle seems to be about 20-22 degrees at idle with spout in. Would a 50% duty cycle be ideal? Or would you need a little less maybe 35% to allow for worst case scenerio added load at idle?

Thanks in advance......
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Re: Ideal Idle Air Duty Cycle with warm engine and zero load

Unread postby decipha » Fri Jan 12, 2018 3:45 am

ideally the iscdc should be just about shut at a warm stable idle ~10%

anything less than 35% is fine
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