Fuel Transfer Pump

Access to the Transfer Pump is from the top of the fuel tank, reached by removing the rear seat bottom cushion and then an access cover. The O-ring seal between the pump and the fuel tank should be replaced whenever the Transfer Pump is removed and installed.

1. Remove the rear seat bottom cushion. Remove the Transfer Pump and fuel gauge sending unit access cover by removing the three (3) mounting screws.
2. With the ignition switch OFF, disconnect the coil wire from the center tower of the distributor cap and connect it to ground on the engine block using a jumper wire.
3. With the transmission in PARK or NEUTRAL, and the parking brake set, have a partner operate the starter for 3 to 4 seconds. While the starter is running, and for a few seconds afterward, you should be able to hear the Transfer Pump running from the rear seat area.
4. If the Transfer Pump is not running, bypass the fuel pump relay as described below.

OPERATING FUEL PUMP FOR TEST

5. 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.

Relay Terminals:

6. 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 the sockets of the fuse/relay panel, which correspond to terminals #30 (battery power input) and terminal #87 (output to fuel pumps) of the fuel pump 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.

7. With the ignition switch OFF and the fuel pump relay removed, use the jumper wire assembly (toggle switch OFF) to bridge the sockets in the fuse/relay panel. Turn the toggle switch ON to operate the fuel pump.
8. If the Transfer Pump still does not run after bypassing the fuel pump relay, check for voltage at the Transfer Pump harness connector. If voltage is reaching the connector, the Transfer Pump is probably faulty and should be replaced.

NOTE: On the Transfer Pump harness connector, the fuel gauge sending unit and the Transfer Pump share a common harness connector. It may have three or four terminals, depending on the model. Refer to CHASSIS ELECTRICAL DIAGRAMS to identify the correct terminals and wires for a particular model before testing.

Transfer Pump Output Hose:

9. If the Transfer Pump runs after bypassing the fuel pump relay, check its fuel delivery rate. Remove the hose from the Transfer Pump outlet port and plug the hose.
10. Temporarily connect a hose to the pump outlet port. Place other end of hose into a fuel safe measuring container.

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 CIS-E Motronic. 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.

11. Using the jumper wire assembly at the fuse/relay panel as described above, have a partner run the Transfer Pump for exactly ten (10) seconds while you hold the fuel hose in the measuring container.
12. The Fuel Transfer Pump should deliver at least:

10 oz. (300 cc) in 10 seconds

Fuel Transfer Pump:

13. If too little fuel is delivered in the preceding test, remove the Transfer Pump and inspect the pickup strainer/filter for blockage, refer to COMPONENT REPLACEMENT AND REPAIR PROCEDURES.
14. Retest the Transfer Pump delivery rate, if fuel delivery is still too low the Transfer Pump is faulty and should be replaced.