Hello again my motor is a 1996 7.4 mpi efi mercruiser and im haveing problems with the motor bogging out when i give it throttle it acts if its not getting enought fuel but the plugs are burining very rich, when i run the throttle up siting on the trailer i get the rpms up to like 1200 and it starts surging loseing like 100 rpm up and down , ive replaced tghe fruel pressure regulator no change changed all tghe ing parts cap rotor plugs , map sensor cleaned out the vst tank that was very dirty still no good it has to much fuel pressure it bounces between 60 and 80 i applied vaclume to the fuel pressure regulator and no change in fuel pressure , pull of the return line to vst and did same test no change in pressure and a stream of fuel about the size of a pencil lead back to a can i rigged. the motor will idle great doesnt miss or anything but when im out in the water it will go at 1000 rpm all day fine but as soon as i advance the throttle iti wants to startto surging and if i advance to fast it will bog and die any help will be appericated thanks james