Part 1 of 2

Diagnostic Chart:

Fuel System Wiring Diagram:

DESCRIPTION:

This procedure tests for fuel pump's ability to deliver fuel to the injector fuel rail, the fuel injectors to deliver a metered quantity of fuel, and the vacuum signal to the regulator to control fuel pressure.

NOTES ON FAULT TREE:

1. A remote start switch can be used to actuate the fuel pump through the fuel pump prime connector.

2. The power balance test (chart A-4) will help isolate the leaking injectors. If there is no rpm change when an injector is shut off, that injector may be leaking. To determine whether the fuel pump or pressure regulator will not hold pressure, install tool J37287-2 in the return line and shut off the valve to restrict the return line. Pressurize system. If the system DOES NOT hold pressure, replace the fuel pump, if the system holds pressure replace the pressure regulator.

3. To determine whether the pressure regulator or fuel line is restricted, install J37287-2 in the return line and open shut-off valve. Place one end of tool in a container to catch the fuel and pressurize system. If pressure is above 50 psi, the regulator is not working properly, below 45 psi, the fuel line is restricted.