Main Fuel Pump

Fig. 3 Fuel Pump Terminals:

1. Ensure battery is fully charged and starter motor operates properly.
2. Disconnect battery ground cable.
3. Check resistance at main fuel pump negative terminal (R1). Fig. 3.
4. Correct resistance is less than 1 ohm.
5. If resistance is not as specified, check for circuit continuity between pump (1) and vehicle ground point. Fig. 3.
6. Remove injector/main relay and connect battery ground cable.
7. Engage starter motor. Minimum voltage at fuel pump positive terminal (U1) is 9 volts.
8. With engine running, minimum voltage at fuel pump positive terminal (U1) is 12 volts.
9. If above voltage readings are not correct, check the following:
a. Circuit continuity between pump (1) and the tachymetric relay.
b. Fuel pump fuse.
c. Tachymetric relay.