[Beav]

Originally Posted by lee

Re-checked MAF sensor connection and air intake tract, found a small hole where a hose on the driver's side connects to the plastic housing - bottom of two hoses near where it connects to the throttle body (part of the PCV system I think). Fixed that - tiny, tiny improvement.

Any leak between the MAF and the engine will cause a problem, be sure you don't have more leaks. Sometimes it is necessary to remove the entire tract and check it closely, particularly in the convoulted area.

Tried to test the EGR valve by putting a vacuum on the valve - couldn't get to more than about 5", but engine stumbled a bit, so I'm assuming EGR is functional.

At least the valve is good and not clogged. Still no idea of how each port is flowing though.

Interested that I couldn't get a decent vacuum, I did some close listening (at idle), and I heard what sounds like an air leak.

Were you using a vacuum gauge? How much vacuum do you have @ idle? Try using flammable carb cleaner, spraying near hoses and mechanical joints to find leaks.

Took the top black pieces off the intake manifold and it definitely sounds like an air leak somewhere under the manifold - loudest when I put my ear near the opening where the PCV valve is located.

I wish I could remember what it should sound like....So, my question - is this air leak sound normal, or do I need to pull the manifold & replace hoses, etc.?

I hear ya buddy. It's especially difficult to differentiate the noise that is normal from a bonafide leak. You should try listening to newer engines with plastic manifolds! My experience is that going by sound alone is a sucker bet anymore. Use the carb cleaner.