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.

 

The air pump and ACV simply injected air and some unburnt hydrocarbons into the catylatic converter. On the lower intake manifold, there should be a tube going from there to the cat. Just make a block-off plate for the ACV and remove the air pump (block-off the hole left in the air box). The pros: reduces weight and a minimal HP gain. Cons: not emissions-legal and can cause you not to pass smog. So, if you don't have to smog test your car, take it off. Also, block-off the EGR valve (under the intake manifold) and remove the vacuum/solenoid rack for the full effect. Make sure to cap the cavuum sources off, and make sure your FPR has a vacuum source (or even the solenoid if you wanted).

 

I see. What is the FPR?

 

Fuel pressure Regulator; it's attached to the fuel rail and has a vacuum hose going to it. Basically, the vacuum your engine produces (full vacuum at idle, and no vacuum at wide-open throttle) determines the pressure your fuel injectors receive. More vacuum = less pressure; it (the FPR) really helps to fine-tune the idle/cruising air/fuel mixture. When I remove all the emissions stuff, I just hook the FPR to a spare vacuum nipple (similar to how every other car I've ever seen is hooked-up).