K 3500 Truck 4WD V8-6.0L VIN U (2002)
14. This step tests for a restricted fuel return pipe. If the fuel pressure is within the specified values, there is a restriction in the fuel return pipe.
16. This step determines if the fuel pressure regulator or the fuel pump is the cause of the low fuel pressure. If the pressure rises above the specified
value, the fuel pump is OK.
18. This step verifies that a circuit condition is not the cause of a fuel pressure concern. Thoroughly inspect all fuel electrical circuits.
