Thread: Air regulator question

so i've been having the dreaded cold start issue here in the last couple weeks. it seemed that the air regulator would be a good culprit. my question is how much does it open up? i took it off and gave it twelve volts and it only opened maybe a 1/16th or so. is this normal or does it actually open all the way as in the same opening as the port you look through? thanks for the help.

Jamie

Why would you arbitrarily give it a 12v signal?

because that is what it gets to close it unless i'm misinformed. from what i understand when you turn the car on it gets 12v to the heating element inside which closes it.

Are you talking about the AAC, or the IACV? I assume you're referring to AAC, since you're talking about cold starts. The AAC is temperature controlled, not voltage controlled. As the coolant temp increases, the thermo plates adjust the opening.

well i guess i read wrong somewhere and yes i'm talking about the aux air regulator that just opens and closes for cold starts not the idle air motor. so aside from the ohm test on it you have to subject it to hot or cold to see it work properly? not to sound like a smart as* but what does the plug going to it do then if it's controlled by coolant temp? again not trying to be an as*.

The ECU needs to see AAC input so that it can correct for A/F mixture. If the valve is fully closed on cold start, the ECU won't know unless it's hooked up

ahh, makes sense. thanks for the input. so to check it could you stick it in the freezer to make sure it shuts and pour hot/boiling water through it to see if it opens?

You are correct that you can test it with 12 volts. No water involved at all. It should pass air when cold and when the 12 volts is applied it will close over time, at that point is should no longer pass any air through. The ECU knows nothing about what this valve is doing. It is used to give the really fast idle when the car is cold.

Symptom of failure is car needs throttle open to start when cold, then will die if you don't keep the throttle open. After maybe a minute or 2 it will run ok. This is not the time of year when it should give you much problem though. They usually fail such that is is stuck closed.

Agreed. The colder it gets the more it opens.

i thought i saw where you could test it with 12V. and i agree that i wouldn't think it would be much of a factor this time of year either. i did go home and stick the one i just swapped out in the freezer to see if it'd open and then let it sit in the garage to see if it would shut again and it did. so i guess i'll be trying the temp sensor, idle air motor, etc next. thanks for the help.

Jamie