I really doubt the air/fuel mix is related.
I would be very meticulous to see if there is a small leak that is hardly detectable and allowing air into the system. I can't help but wonder if there is a small crack in the head that is only opening under extreme load.
I think, I would pressure test it and let it set overnight and see if anthing appears in the morning. For that matter, pull the plugs first and look at them carefully for any signs of green.
If nothing is obvious in the morning, gently back out the oil drain plug and look closely at the first two drips to make sure oil comes out and not coolant. The coolant will settle to the bottom of the pan if it is present. If still nothing. Crank the engine over and see if anything shoots out the cylinders.
Tuesday, February 20th, 2007 AT 8:42 PM