aac - how the f***

S

stedee

New Member
right ive got the same ol high idle - not that bad but still high
i found the thingy behind the throttle body in the middle lying flat is that the aac or the air regulator or are these the same thing? well anyway how do you get it off without dislocating fingers and a wrist.

also if the aac and air regulator are not the same where is the other one located.

i dont want to mess with the tps or stops until i have at least tried these 1st.

thanx in advance
steve
 
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youngsyp

Active Member
The AAC and air controller are not the same thing. They are all in the same area though, along with the FICD ! :lol:

The AAC is for general idle speed control.
The IAR/IAC or air controller is for when the engine is cold. It will bleed air into the intake, to keep idle speed up and prevent stalling.
The FICD is for when you use the A/C. It will again let more air in when the A/C is switched on, to prevent stalling.

The only way to get good access to any of them is to take the throttle bodies off !

Have you tried squeezing the PCV hose to see if the idle speed changes ?!

Paul
 
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pulsarboby

Guest
the idle speed control valve can be changed fairly easy as the unit screws into the housing it has a spring and plunger inside it so you have to be carefull not to lose it, think its a 17mm spanner. you havent got to change the whole housing.
 
S

stedee

New Member
i wish i could see whats behind there so i could understand whats what.the iac or oar is what i think is wrong because the revs rise when cold and do drop when warmer but they seem a bit hit and miss as its warming up as if the system is sticking abit. which is the one where i can take the pipes off and join them up instead and there is a box on the right hand side of the plenum is that the aac and i can see a screw in it is that for idle adjustment.

why oh why did they stick the bloody things there of all places lol

thanx for your replies
 
Y

youngsyp

Active Member
stedee said:
i wish i could see whats behind there so i could understand whats what.the iac or oar is what i think is wrong because the revs rise when cold and do drop when warmer but they seem a bit hit and miss as its warming up as if the system is sticking abit. which is the one where i can take the pipes off and join them up instead and there is a box on the right hand side of the plenum is that the aac and i can see a screw in it is that for idle adjustment.

why oh why did they stick the bloody things there of all places lol

thanx for your replies
Click to expand...
That's right mate, the valve with the idle adjustment screw is the AAC.

Getting the idle right in all the possible situations is a very hard task. That's why you need the three valves to do it. Of course, that doesn't help when one fails !

I'd start by removing all the PCV valve pipes, along with the throttle body pipes and the charcoal canister. Make sure all those points are blocked off. That will remove a large number of vacuum pipes from the equation and so, narrow down any leaks.

I like Bob's idea of taking the idle screw out too. I had my plenum off recently and should have stripped all the valves down.... however, not to rub it in, mine idles at around 900 - 925 rpm anyway !

Apart from that, it's a case of searching for a vacuum leak somewhere I guess...

Paul
 
Fusion Ed

Fusion Ed

Active Member
It should idle fine with just the AAC valve... thats the main one that deals with idle, and is PWM controlled the others are just on off etc
 
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