What is the function
 

Hi all. I need some knowledge. On the GSL-SE...What is the purpose and function of an air pump & air control valve? Also, if these two items have been removed from a vehicle, what affect would this cause to the car? (Good/bad) Lastly, will it be simple or difficult to restore the two items back into the car? Thanks.

On the GSL-SE and most other cars, the airpump (AP) and air control valve (ACV) are used to meter fresh air into 1 of 2 places. 1) the exhaust ports to cool the exiting exhaust gases during idle conditions, or 2) the main catalyst (there are 3 on an SE, main is the last) during cruise throttle to burn off excess unburned hydrocarbons from the engine.

The AP only provides pressurized air (about 2-5psi) at low volume since it's driven by a pulley attached to the main pulley and waterpump. Since this pump is providing air pressure anytime that the engine is turning, the ACV controls where that pressure goes, since running a pump at 0 flow will cause damage to the pump. The ACV uses vacuum pressure to route the air to where it's needed most.

Removal of these systems will increase unburned hydrocarbons (important if you live in Emission Test states), and increase overall performance slightly, since you're removing a drag on engine performance (the pump). It will also open up several large vacuum leaks that you'll need to plug to get the engine to run correctly, including the ACV mounting point (using a 'block-off' plate), and the inlet to the Main catalyst if you don't also remove cats.

Installation of these parts is fairly straightforward, and a simple installation as long as you have all the gaskets you need, good parts, and good garage tools. HTH,

And another thing - they rarely fail. If an AP seizes on a car, you'll be able to tell from the belt and pulley. If you want to restore them, a junkyard is a safe way to go as long as there's no physical damage, and nobody ever WANTS these things - they're either tolerated or thrown away, so you should be able to find them easily.

also, if you have cats and remove the air pump, you could be in for trouble. the converters will melt down and clog and overheat. it will also cause a TON of backpressure. not good.

So the air pump can be easily found and replaced. How about the ACV? Can I just go grab a used ACV from a parts car or junkyard without having to worry about getting it brand new?

definately try to find a used acv, i think they are very expensive brand new.

check around here for the acv. both are easialy replaced and decently easy to aquire.