I know the aux air valve will raise the idle when the motor is cold by using vacuum to open the throttle body just a tad... when warm coolant flows through the aav, it no longer sends vacuum to the throttle body and will lower the idle speed. It's all mechanical, so what does the plug on the back of the aav do?

I would assume that it would tell the ECU to send a little more gas to the engine to help raise the idle, but that's what the cold start injector, temp sensor, and csi timing sensor does... right? Is it just redundancy?

 

what year is the truck and what motor do you have. in 86 on a 22re the aux air valve is mechanical. just lets more air into the intake. there is an adjustment on the top of the intake near the front. the aux air valve is also adjustable on the back with a tiny screw that turns the plate inside the valve.

 

The AAV uses the temperature of the coolant to allow air to bypass the throttle plate using a wax type valve just like the thermostat, except it opens when the coolant is cold, and closes when its warm. The bypassed air is sensed by the O2 sensor, which tells the ECU to keep the injectors open longer, which introduces more fuel in to the engine, increasing engine RPM.
Cold start injector only puts more fuel in while cranking. The temp sensor to the ECU basically tells it to stay in open loop because the engine is cold. The CSI timing sensor just determines when and when not to inject more fuel.
I'm not sure what plug you are referring to. I dont remember there being one on the back of the AAV, but its been a while since I have been through there....
22re? or 3vze?

 

On the early 22REs, the air valve has an electrically heated coil inside it. The coil does the same thing as the coolant loop, heats up a bi-metal strip that causes the valve opening to close.

 

This is on an 88 22re. As my motor sits now I don't have any hoses going from the AAV to the throttle body and manifold. I am contemplating buying them from the dealership but I'm trying to learn as much as I can to determine if it's worth spending $40 on two little hoses.

I don't have any cold start or idle issues so I'm wondering if it's a waste for me to buy those hoses. Currently I just have the air ports on the throttle body and manifold capped and don't have any issues. It's only got down to the mid 30's so far, but still no starting or idle issues.

 

.....

 

Thought I would bump this. I have an 86, and put a new engine in it. My question is what color are the wires to the plug of the aav? I can't find it in my wiring diagram. Thanks

 

another question....what do the adjustments do? because my 22re will only idle high when its about 25 F or below. i would think it should idle at least a little high all the time during a cold start.

 

You must remember on engines this old lots of these AAV`s have just failed from old age.

Over the years i have disconnected quite a few since they didn`t work no major changes in starting.