Hi everyone,
Does anyone know what signs would show when the Idle Air Control Valve needs to be cleaned or replaced?
Thanks everyone,
Geoff.
Idle Air Control Valve???
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supersnake83
- Posts: 142
- Joined: Mon Dec 26, 2005 6:20 am
- Car: Infiniti J 30
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Re: Idle Air Control Valve??? (supersnake83)
The normal way is to observe the IAC duty cycle with a Consult.
After reaching coolant stabilization [176F] the IAC should only need to provide another 10% over what flow in the manual bypass [adjustment screw] and under the closed throttle plate.
Each addition engine load should increment the percentage [lights, turning power steering, ac compressor on, rear defroster] to a max of 25-35% at idle in park.
Studying the duty cycle steps/increments as you increase driving speed to cruise shows you how the IAC acts as a dashpot when you suddenly lift of throttle to keep engine from stalling and coast down the car speed in increments.
Depending on local air and oil dirt the IAC should be removed and cleaned internally every 60,000 miles.
It/ with Consult tells you when the throttle body and plenum and pcv valve need cleaning because the perfect 10% duty cycle starts to creep up 15%.20% as the other air path's get dirty and restrict air low.
After reaching coolant stabilization [176F] the IAC should only need to provide another 10% over what flow in the manual bypass [adjustment screw] and under the closed throttle plate.
Each addition engine load should increment the percentage [lights, turning power steering, ac compressor on, rear defroster] to a max of 25-35% at idle in park.
Studying the duty cycle steps/increments as you increase driving speed to cruise shows you how the IAC acts as a dashpot when you suddenly lift of throttle to keep engine from stalling and coast down the car speed in increments.
Depending on local air and oil dirt the IAC should be removed and cleaned internally every 60,000 miles.
It/ with Consult tells you when the throttle body and plenum and pcv valve need cleaning because the perfect 10% duty cycle starts to creep up 15%.20% as the other air path's get dirty and restrict air low.
Re: Idle Air Control Valve??? (Q45tech)
Can some one highlight me on how to remove and clean the idle air control valve, much appreciated.
Re: Idle Air Control Valve??? (redboeing)
that would be a nice project for the weekend, i have been having some problems with the idle lately, when i come to a complete stop, the rpm goes down to less than 500 and then back up to 750, however, the engine idles at a constant 750 when the AC is on, i'd appreciate your input on the cleaning procedure