FDS10 - Check Regulator For Low Pressure Causes

^ Key Off.

^ Remove return fuel line at fuel rail and connect short hose from rail to measured container of at least one quart capacity.

^ Ground Fuel Pump (FP) lead as in Step FDS2.

^ Key On, Engine Off.

^ Record fuel pressure and note whether fuel is being returned to measured container. Unground FP lead after 10 seconds or if container is more than half full.

^ Is fuel being returned after pump is turned off?

YES -- Replace fuel pressure regulator. Repeat Test Step FDS2 for verification. FDS2 - Fuel Pressure Test

NO -- Replace fuel pump assembly. Repeat Test Step FDS2 for verification. FDS2 - Fuel Pressure Test

NOTE: When replacing fuel pump, clean out tank and replace fuel filter.