Help! What is wrong with my motor?

[Brad T]

I blew off the line to my MAP sensor and leaned out .Now the thing runs fine in the water box and will run up to 7200. But when I try to make a pass it hits about 6300 and starts to flutter and will not pull any higher under load.It doesn't seem to have any blow by and everything looks good on the speed-pro.I've changed plugs ,wires,coil and module but no change.Is it possible it is a bad head gasket ?I've blown a few on the stock block but never on a stage II block.Can they act like this and not spew water out ?

 

[750H.P.V6]

Brad,

As a guess I'd say that you hurt a head gasket. Go ahead and do a compression check and you will more than likely find two adjacent cylinders with little or no compression. If this is the case this would indicate you burned the gasket between cylinders. This type of gasket failure won't produce any excess crankcase pressure, water in the oil, or compression in the waterjacket. Check it out see what you come up with.

Good Luck

Neal