'7747 & two A.I.R. valves - CrossFire retrofit

[Ken Kelly]

Alright, I did some more searching this afternoon and went through the
DIY-EFI FTP site and found the ASDU bin, which is for a 1990 Chevy Pickup
with 350/auto.. I looked up on CarParts.com as to what it had, and it has
both of the A.I.R. valves as well as the Cannister Purge valve.

>>>The port solenoid (EAS, pin C2) controls air to the manifold.
>>>The divert solenoid (EAC, pin C1) controls air to the cat-con.

So pin C2 controls the valve that's right off the pump - that changes
direction to the air cleaner assembly during deceleration, and the other
one - pin C1 - controls the valve that changes direction from the manifolds
to the cat converter? (When you're in open loop?) Am I correct on this?

Reading some of the other replies, it sounds like you could literally
disconnect the A.I.R. system and be scot-free on emissions - it'd be cleaner
than before. Would the extra oxygen HURT the system? (Would it improve
emissions over say a non-A.I.R. system?) I'd honestly rather use the system
that's in it - but that's mostly because of the strict emissions policies
here in Houston. They do a visual check as well as a tailpipe sniffer.
(Although they don't test for NOX, so I can disconnect the EGR!) I might be
able to get away with making a seperate calibration for running with the
belt off the A.I.R. pump, and just putting the belt on when inspection comes
(and a new chip in that gives me clean emissions.)

>>>ASDT and ANSY are for a 2.73 rear gear ratio, ASDU and ANTA are for all
others.

My '82 Corvette has something like a 2.87 ratio, maybe even 2.73. Should I
use ASDU, or ASDT? (What's the difference?)

Thanks again for all the helpful replies!

Ken


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