Have a hpdi lz150txrz 6k0x800776 that will not run after start up .Fuel pump pressure is just below 60 psi at the vapor separator and does not drop off at the point of stalling.Injectors have been rebuilt and 2 replaced new.Compression numbers looked good as did ignition output.Engine will start and run great for a moment then stall.No external fuel leaks are apparant.This is a twin application with both engines sucking off the same tank.Not the best scenario plus it has twin electric primers at the water separator.Can I adapt Mercs optimax fuel and air pressure guage to this format?