DESCRIPTION & OPERATION
The electric fuel pump used on carbureted models is an electromatic plunger type pump. The fuel pump on fuel injected models is a pin and roller type electric pump.
The plunger type pump is designed to relieve pressure at 2.6-3.3 psi (.18-.23 kg/cm 2 ). The pin and roller type pump is equipped with an integral relief valve which is designed to relieve pressure at 61-71 psi (4.3-5.0 kg/cm 2 ).
A fuel damper is mounted on the end of the pump to reduce changes in the fuel pressure generated in the system. All pumps are mounted in front of fuel tank. The fuel pump is actuated when the ignition switch is in the "START" or "ON" position. A check valve, located on the fuel pump outlet, prevents fuel from returning to the fuel tank when the engine is turned off.
Scheme 49
TESTING
Before performing the following tests, ensure hose and electrical connections are tight. Confirm fuel pump makes an operating sound when actuated.
Scheme 50
Carbureted Models
Disconnect fuel hose from carburetor. Connect a pressure gauge to fuel hose. Measure output pressure while operating fuel pump. Pump output pressure should be 1.3-2.0 psi (.09-.14 kg/cm 2 ). If output pressure is not as specified, replace the fuel pump.
Fuel Injected Models
- Unplug the fuel pump electrical connector. Crank engine for 5 seconds to relieve fuel system pressure. Disconnect fuel hose at the fuel pressure regulator. Install a fuel pressure gauge in-line using a "T" fitting.
- Fuel pressure at idle speed should be 26-30 psi (1.8-2.1 kg/cm 2 ). Increase RPM and ensure fuel pressure increases correspondingly.
SUCTION TEST
Disconnect fuel hose between fuel filter and pump at the filter. Place finger over end of hose. Suction should be felt when fuel pump is actuated. If no suction is felt, replace fuel pump.
Note. Relieve fuel system pressure prior to disconnecting fuel hoses.
Removal & Installation
Disconnect wiring harness from fuel pump. Disconnect and plug fuel lines from pump. Remove fuel pump from bracket. To install, reverse removal procedure.