Originally Posted by cobalt327
My theory is a too low float setting. This is allowing the engine to effectively drain enough fuel to cause the porpoising as the pump refills and the engine subsequently uses the fuel from the too-low float bowl.
Along w/the low level sloshing back and forth- causing the jets to cover then uncover- would cause it as well.
The raising of the pressure effectively caused the fuel level to behave as if it were higher.
Yep, this could be correct as well.