I logged some drive time, about 10 minutes and wanted a second opinion. It looks like everything points to an intake leak, but I just can't find it. Anyway, I'm having a problem with split BLMs.

Closed loop starts at record 2038. There is a short period of idling and small reving at 5788.

http://members.shaw.ca/swds.mlowe/Car/May22-CZ28.csv
http://members.shaw.ca/swds.mlowe/Car/May22-CZ28.uni

Comments:

The exhaust is very loud and exits 2 feet back from the header collectors. That's causing all of the knock retard. I'm waiting for a y-pipe to arrive and then I'll have a quieter system.

I'm 95% certain there're no exhaust leaks. I have locking header bolts and I can't feel escaping exhaust anywhere. I've checked for intake leeks by feel... is there a better way to do it?

This problem didn't just "happen," it showed up after a LE2 head/cam install. I used new GM intake gaskets, ultra coper RTV, and did everything by the book. I haven't traced all of the vacuum lines for cracks yet, but I have checked all of the connections near the intake manifold.

So my questions are this:

1) Does everyone else think it's a vacuum leak too?
2) The vacuum is quite low at idle, around 7" Hg. What should an LE2 cam pull for vacuum?
3) If a cylinder was not firing, or the valves were not adjusted correctly, would I see similar data logs?

The car shakes a little at idle, but I'm figuring that's just the exhaust resonating the 3 immediate city blocks. At 1500 RPM+ it's very smooth.

Mods are: LE2 heads/cam, LE ported intake, 1.6 Comp Mag RRs, 58mm TB, Hooker LTs, 3" custom CAI.

 

ttt