Probably the fuel pump on its way out, a common problem sadly. There is a better fuel pump that can be fitted into the same fuel pump module, a Walbro GSS342 that should be redly available in the USA. If you are still in warranty then get your dealer to replace the pump unit with a standard one, it should last a few thousand miles. The ECU fault codes will need resetting after the pump change. The pump output can be checked ot the test point on the LH injector, it should be 58 psi.
