the fuel pressure changes less than bar from idle to full throttle, if it has fuel pressure at idle then it is fine
i wonder if the 2.4 manifold has a crack or isnt sealed properly, the map sensor is like the maf sensor in that it will control injector pulsing and the throttle body position as i found out
on the 2.2 manifolds if you unplug the nipple on the side to allow unmetered air in, then the ecu compensates by closing the throttle body even more, something like a 50% difference at idle