Originally Posted by
kingtal0n
because you seem to ignore electrical ground issues and map sensor calibration with engine on vs off (which relfects an alternative ground resistance pathway to the voltage sensors) The only way to resolve this issue is to post a LOG of the engine in question at WOT from say 2,500 RPM to around the 5,000 rpm range so we can compare the map sensor voltage or KPA values first to see if there is truly a restriction or issue.
Next, the intake manifold (any) at WOT with no air filter and no intake pipe should be fairly atmospheric for all but the most high performance engine vs displacement, therefore if there is some pressure drop present under those conditions I Would suggest that the intake valves are not sealing or there is some leak somewhere