Main Pump
FUEL PUMP TEST1. The Fuel Pump runs whenever the ignition switch is turned ON, but will stop automatically if the engine stops running or fails to start. Listening under the rear of the car, you should be able to hear the pump run for a few seconds when the starter is engaged, or the ignition switch is turned ON. If the Fuel Pump does not run, first check the fuel pump fuse (#13) at the fuse/relay panel. If the fuel pump fuse is GOOD continue with test.
2. Unless the fuel pump relay receives an rpm signal from the ignition system indicating that the engine is running, the fuel pumps will operate for only a few seconds when the ignition switch is turned ON. To operate the pumps longer, (for example fuel system tests without the engine running) the fuel pump relay must be bypassed to power the pumps directly.
NOTE: Some vehicles are equipped with a knee bolster to prevent knee injury in the event of an accident. The knee bolster runs along the entire length of the lower dash. To properly access the fuse/relay panel for servicing, the knee bolster must be removed from in front of the fuse/relay panel.
Fuel Pump Relay Location:
3. One method is to remove the relay and connect a jumper wire between two sockets on the fuse/relay panel. The sockets to be used are socket #48 and socket #52 of the fuse/relay panel, which correspond to terminals #30 (battery power input) and terminal #87 (output to fuel pumps) of the relay
NOTE: The jumper wire should be at least 16 ga. (1.5 mm) wire and include an in-line fuse holder with a 15 amp fuse. To avoid fuse/relay panel damage from repeated connecting and disconnecting, also include a toggle switch in the jumper wire assembly.
4. With the ignition switch OFF and the fuel pump relay removed, use the jumper wire assembly (toggle switch OFF) to bridge the sockets (#48 and #52) in the fuse/relay panel. Turn the toggle switch ON to operate the fuel pumps as needed for testing.
5. If the Fuel Pump does not run normally, but will run with the jumper wire assembly turned ON then the fuel pump relay or the fuel pump relay wiring is faulty. If the Fuel Pump will run only with the jumper wire assembly turned ON, and no faults are found in the wiring to the fuel pump relay, then the relay itself is faulty and should be replaced. For testing procedures of the fuel pump relay and it's wiring Fuel Pump Relay
Fuel Pump Electrical Testing:
6. If the Fuel Pump still will not run with the jumper wire assembly turned ON, check to see if battery voltage is reaching the Fuel Pump. Disconnect the two electrical connectors from the Fuel Pump. With the relay removed, the jumper wire assembly connected and turned ON, the ignition switch ON, check for voltage at the fuel pump connectors. If there is voltage, then the connection or the Fuel Pump is faulty. Replace the faulty Fuel Pump. If there is no voltage, look for a faulty wire or connection between the fuel pump relay and the fuel pump connector.
FUEL PUMP DELIVERY RATE
Fuel Pump Delivery Rate:
1. Disconnect the fuel return line in the engine compartment. Direct the open end of the return line into a gasoline-safe measurement container of at least 1 quart (1000 ml).
WARNING: Fuel will be expelled when the fuel lines are disconnected. Do not disconnect any wires that could cause sparks. Do not smoke or work near heaters or other fire hazards. Keep a fire extinguisher handy.
CAUTION: Absolute cleanliness is essential when working with fuel circuit components of Digifant II. Even a minute particle of dirt can cause major trouble if it reaches the fuel distributor or fuel injectors. Before disconnecting any of the fuel line connections, throughly clean the unions. Always use clean tools.
2. Energize the Fuel Pump using the jumper wire assembly for exactly:
30 seconds
3. The pump should deliver at least:
17 oz. (500 cc)
NOTE: To obtain the most accurate test results, do not loosen the fuel tank cap until testing is complete.
4. If fuel delivery is below specifications, check for leaks, blocked or kinked lines, a clogged fuel filter or a blocked transfer pump strainer/filter. If no such faults are found, the Fuel Pump is probably faulty and should be replaced.
5. The Digifant II fuel injection system is dependent on high fuel pressures to operate properly. The Fuel Pump must meet these pressure demands any time the engine is running. Therefor, testing the Fuel Pump pressure output should be done to ensure the Fuel Pump is indeed GOOD. For pressure testing the Fuel Pump Fuel System Pressure Test