I tried adjusting the idle set screw. Since it is near impossible to get anything in the back of it to adjust it, I used a pair of vice grips and clamped onto the part of the screw that was sticking out and turned it that way. I had the set screw almost all the way in and my IAC was only reading in the 60's. My rich condition remained, so this didn't solve my problem. Hope you have better luck

 

Well, worked on it again this weekend and adjusted the idle screw, new IAC, cleaned IAC ports, but still no luck. The split is only at idle and after 1200 rpm's and under normal driving the BLM's level out. Didn't wanna do the IAC drill mod or the tube mod to the plenum as the BBK tb's don't have the cross vent the ASM's do and the IAC passage is sealed up tight to the manifold entrance. Really, don't know what else to do, so I think I am gonna just leave it for now as it is only at idle, not getting any knock and doesn't seem to hurt performance. If anyone else has any more suggestions let me know but I think I am at the end of my rope here.

 

Thats sucks to hear man. I was hoping at least one of us was going to have some luck so we could help the other out haha. Well, feel lucky you can at least drive you car. I can't pass smog here in California since they test emmissions at idle and 2500 rpm. Since idle is where my problem is, I fail that part of the test but pass 2500 rpm just fine. I haven't been able to drive my car legally in over 6 months I'll PM you if I ever figure it out.

 

I have been stuggling for a long time with this and I finaly figured it out. for me atleast. I did drill a hole in the TB IAC passage as seen in the previous threads, and it didn' t completely help. The thing is that no matter what size the hole is or how wide open the IAC is, if your not stock the holes in each individual intake port are only so large, they let in as much as the stock motor needs, I found this out by accident when redoing my heads. I had my intake ported buy Lloyd Elliot. I noticed that 4 of the 8 IAC plenum holes in the intake ports were also ported out and some were not. I am by no means saying Lloyd did any thing wrong, I do think they may have accidentaly missed a couple of the hole, SO I matched the hole size to a drill bit and finished the job, I also backed off the 4 large allen head Plugs (no Idea the correct turm for these) that expose the bottom of these intake IAC passages by one thread length before torqueing and sealing them.

Guys I'm here to tell you that the combination of tuning the IAC counts, drilling the bypass hole in the TB and port mattching the IAC Plenum holes into the intake ports has giving the IAC the volume and less restriction to let it keep up and regulate correctly, not just opening the Blades and dumping air randomly into the main Plenum. The combo worked after 6 years of splits...hope this helps.

 

Glad to hear you resolved this. However, I want to emphasize that you didn't have to do all you did. The TB drilling mod is what should work.

Look at my cam and I think it is more radical than yours (not sure of LE3 spec's). All I did was the TB drill mod and I have perfectly balanced BLM's. Now, I COMPLETELY closed the blades at idle so ALL air at idle goes through the "idle air plenum". This is the part most people miss.

 

What computer are you using to run the engine? If its a camaro computer may I take a look at a datalog and possibly your tune? I'm working on ign timing right now, I have pretty much got the Vol Eff tables done with VE master and fine tuning when driving. But I'm trying to iron out tip in of idle and when shifting from 1st to 2nd with a 3500rpm TC and WOT its not hitting like I'd like. Thanks.

Oh and I acctually stumbled onto the intake holes when the intake was already off, I was correcting alot of other issues at the same time with the head reinstall. That just kindof happened out of convienence.