Voltage at AAV terminal

[Turbofiat124]

Is there any real reason to get this valve working? Or is this one of those emission control devices that is simply there to help get the engine hotter so it burns cleaner?

It is not an emissions control device. It increases idle speed by passing more air into the manifold during cold running.

Yeah I know what it does. But what I'm saying is if I start the engine and it's cold outside (32F) and the engine idles at 1000 rpms just as it would when the engine is at normal operating temperature without stumbling is the valve needed?

I'm thinking it's not really needed on a fuel injected engine where the fuel mixture is better controlled.

I had some issues with the electric, then the coolant controlled choke on my Yugo I finally just went with a manual choke. It works better but there is no fast idle provision for it. So the idle speed is a bit lumpy until it warms up.

[bradartigue]

Is there any real reason to get this valve working? Or is this one of those emission control devices that is simply there to help get the engine hotter so it burns cleaner?

It is not an emissions control device. It increases idle speed by passing more air into the manifold during cold running.

Yeah I know what it does. But what I'm saying is if I start the engine and it's cold outside (32F) and the engine idles at 1000 rpms just as it would when the engine is at normal operating temperature without stumbling is the valve needed?

I'm thinking it's not really needed on a fuel injected engine where the fuel mixture is better controlled.

I had some issues with the electric, then the coolant controlled choke on my Yugo I finally just went with a manual choke. It works better but there is no fast idle provision for it. So the idle speed is a bit lumpy until it warms up.

Your car shouldn't idle at 1000 RPM when cold without the AAR, the thing is calibrated to deliver a certain amount of air to keep the idle high. It's not a choke, it is exactly the opposite (it does not restrict airflow but increases it to elevate the idle speed). I'm not sure what your car is doing, but assuming it is working without it then sure, remove it. We used to remove them from early Porsche 928s because the tubing to and from the device was a nightmare, with a weird S shaped hose and funky clamps...you just got used to a lower idle for the first minute or so.

[Turbofiat124]

It is not an emissions control device. It increases idle speed by passing more air into the manifold during cold running.

Yeah I know what it does. But what I'm saying is if I start the engine and it's cold outside (32F) and the engine idles at 1000 rpms just as it would when the engine is at normal operating temperature without stumbling is the valve needed?

I'm thinking it's not really needed on a fuel injected engine where the fuel mixture is better controlled.

I had some issues with the electric, then the coolant controlled choke on my Yugo I finally just went with a manual choke. It works better but there is no fast idle provision for it. So the idle speed is a bit lumpy until it warms up.

Your car shouldn't idle at 1000 RPM when cold without the AAR, the thing is calibrated to deliver a certain amount of air to keep the idle high. It's not a choke, it is exactly the opposite (it does not restrict airflow but increases it to elevate the idle speed). I'm not sure what your car is doing, but assuming it is working without it then sure, remove it. We used to remove them from early Porsche 928s because the tubing to and from the device was a nightmare, with a weird S shaped hose and funky clamps...you just got used to a lower idle for the first minute or so.

I have my idle speed set at 1000 because the engine sounds smoother than at 700 (or 800) rpms as the factory recommends. Well 1000 rpms according to the in dash tachometer. I know you are not supposed to go by that thing and use a tune-up tach instead...

So it idles at 1000 rpms when cold or normal operating temperature.

Sorry for throwing in the carbureted content. That may have been confusing. I know the AAV is not to enrichen the fuel mixture. I was just saying since I did away with the automatic choke on my Yugo, this also did away with the fast idle mechanism. On a carbureted engine, the fast idle mechanism seems more essential than on a fuel injected engine. I would assume the reason a carbureted engine idles lumpy when cold. That was what I was getting at.

[bradartigue]

If you have it set at 1000 then you're overriding the AAR to begin with, so sure, you don't need it.

[That]

So, now I am confused with all these theories and explanations. My understanding is this. The 12v power to AAV is simply to power a heater, of sorts , inside the device and cause the little door inside to close quicker. I cleaned my AAV with carb cleaner then soap and water then air dried it. Stuck in freezer for an hour and you could see opening about size of a kitchen match( if any if you remember those ) so I then laid it out in sun for an hour or so and it closed up. Temp about 70f. As long as it returns to open position when engine cold, doesn't really matter if it takes 10 min, or 5 min or whatever to fully close. There is plenty of hot air under my hood to close this AAV. So, I'll leave it alone. Seems to be working ok.

[bradartigue]

It's not a confusing device, it works just as you described, heat causes a metal strip to cover an opening. Heat is generated by a resistor on the strip, powered by 12v, or by engine heat, or both.

[That]

Many thanks to all you guys (who are much more knowledgeable than I am) whether it works or not, I do understand how it works. That's important to me. What a wealth of information available to anyone!! Again, my thanks to you all.