losing fuel pressure
 

I bought this 1998 Shabah brand new and only have 130 hrs on it. It has the MFI 7.4 Bravo 3. Not a single problem with it till now, even though its been stored most of its life. The boat won't run over 2000 rpm under load. I put a fuel pressure gauge on it and it reads a steady 38 psi with key on only and when engiine starts. You can rev engine to high rpm by itself and no problem other than the pressure gauge seems to gyrate quite a bit. When you take boat out it shows 38 psi but does gyrate on the gauge, but when you hit 2000 rpm fuel pressure falls to almost 0. You can throttle back and it continues to run and pressure comes back up.

I've replaced the fuel filter/water seperater, the distributor cap and rotor (it was pretty corroded), and put the appropriate amount of sea foam in it to treat fuel.

I've found similiar problems on internet blogs and they talk about a small screen filter at the fuel pressure regulator that was clogged. I can't seem to get to this or the fuel pump because there is a plastic cover over these items that is connected to the lower part of the engine block and right up against the fiberglass hull where engine mtr mounts are. Does anyone know how or if you can remove this plastic cover?? Or anyone else had this problem??