I had a problem with a super rich idle, so I drilled two small (1/16) holes in the primary butterflies, and opened up the secondaries a bit. My cruise used to be about a 14-15 afr, now its like 16-20. Does the transition circuit primarily feed cruise or is it the main jets?
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Its a holley 600 dp.

 

I really need some help on this, it just about kills the motor when I try and cruise it, and with a couple lbs of boost going to it, it can't be good. It's lean just past idle but quickly richens up after that on a slow acceleration. Im lost.

 

how did you come to drilling holes in the throttle plates? im assuming you tried to play w/ the idle adjustment, right? main jets should feed cruise. (i'm no holley expert by any means so dont hold me to it.)

 

Of course I tried the idle adjustment, I even messed with the secondary adjustment, but I have the idle afr real close, just cruise is lean. Originally I had wire in the ifr's but that really killed the cruise.

 

The transition circuits on a Holley still have a significant effect on your cruise mixture. I'm not talking about a 100 MPH Autobahn cruise- I'm talking about a 45-50 MPH in-town kinda cruise.