Test NS-4B - Checking Fuel Delivery
WARNING:
High fuel pressure may be present in fuel lines. Open fuel system with caution. See FUEL PRESSURE RELEASE
procedure in this article
NOTE:
For connector terminal identification, see CONNECTOR IDENTIFICATION
. For appropriate wiring diagram, see WIRING DIAGRAMS
at end of article.
- Ensure fuel tank is at least 1/4 full. Turn ignition switch to OFF position. Release fuel pressure. Disconnect fuel return hose from fuel rail. Connect a 6-foot fuel hose to fuel rail return nipple. Put other end of 6-foot fuel hose into an approved 2-gallon gasoline container.
- Using DRB-II, actuate fuel system. Observe fuel pressure gauge. If fuel pressure is more than 48 psi, replace fuel pressure regulator. Perform VERIFICATION PROCEDURE VER-1. If fuel pressure is less than 48 psi, turn ignition switch to OFF position.
- Reconnect fuel return hose. Remove fuel return hose from fuel tank. See Fig 1 . Connect a 6-foot fuel hose to disconnected fuel return hose. Put other end of 6-foot fuel hose into an approved 2-gallon gasoline container.
- Turn ignition switch to ON position. Actuate fuel system. Observe fuel pressure gauge. If fuel pressure is less than 48 psi, replace fuel pump module. Perform VERIFICATION PROCEDURE VER-1.
- If fuel pressure is more than 48 psi, replace restricted fuel return line between fuel rail and fuel tank. Perform VERIFICATION PROCEDURE VER-1.