[Shotimes] Effects of Vacuum Leak on A/F Ratio

[Kurt Metros]

I also posted this on Tech SHO, but would like input from this larger
pool of people.

Now that spring is rapidly approaching (OK, I guess I'm in denial since
it's still snowing and 2-degrees out) I'm ready to get back with Ted
about my LPM programming issues. However, before I do, I wanted to run
something by everyone.

Recently I removed the intake to do some other work and noticed
something that may or may not be part of my problem.  On the bottom side
of the intake, on the several of the runners, where they lead down to
the head, there was a stream of dried dirty water/liquid coming off of
the end of the rubber gaskets that connect the runners to the surge
plenums.  This, and some excess dirt around the edges of the rubber
hoses leads me to believe that the intake has a vacuum leak.  

The issue I'm having with the LPM is that the car is running really lean
at WOT until you get to about 5300 RPM.  At it's worse, the A/F ration
is at 16.0 (around 2,500 rpm) and doesn't get close to 13.5 (where I
think it should be close to for optimum performance) until 5300 RPM.  It
steadily gets richer, but from what I understand, at WOT it should be
around 13.5 throughout the RPM band.

Logic tells me that the vacuum leak would be worse at higher RPM's than
at lower RPM's?  Is this true?  If it is true, then I wonder what's
going to happen to my A/F ration and performance once I tighten up the
leaks??  If not, I may have discovered why I'm running so lean down low.

Am I missing something here?  Any input appreciated.

Kurt
www.kurtmetros.com