WOT too Lean

[blykins]

A restrictive air cleaner will actually richen it up....

Sounds like you have something else going on. Checked for vacuum leaks?

[DanEC]

Originally Posted by blykins

A restrictive air cleaner will actually richen it up....

Oh yeah - well, there's that after lunch duldrums/dyslexia slipping in again.

[blykins]

7 psi is on the high side and I don't really see the pressure making the difference.

If a huge jet size bump didn't make a dent in it, I would look for a vacuum leak at rpm or a fuel flow restriction.

[cycleguy55]

Originally Posted by blykins

7 psi is on the high side and I don't really see the pressure making the difference.

If a huge jet size bump didn't make a dent in it, I would look for a vacuum leak at rpm or a fuel flow restriction.

It would have to be a BIG vacuum leak (20% of total airflow?) to lean out the mixture that much at WOT on a 461 CID engine (Pontiac - cough, hack, gaaack).

I agree with looking at fuel flow restriction somewhere. He'll have to start at one end and go through everything (lines, filters, fittings, pump, etc.) thoroughly and systematically to find out where the restriction is.