Fuel lift pump - testing, removal and refitting

Fuel and exhaust systems - K-Jetronic fuel injection - 8 valve engines / Fuel lift pump - testing, removal and refitting

Testing
1 The fuel lift pump is attached to the base of the fuel gauge sender unit fitted to the fuel tank (see illustration).

18.1 Fuel tank sender unit

Tank and other associated components are identical to those used for carburettor engines

2 If the pump is suspected of malfunction, first check that the pump wiring does not have an open circuit. Remove the luggage compartment floor covering and the circular cover in the floor for access to the sender unit and connections. Detach the wiring connector and make a continuity check between the centre wires and the outer (brown) wire of the connector (see illustration).

18.2 Fuel tank sender unit and connections

3 If the wiring proves correct, then check the pump relay and pump fuse (No. 5). Assuming the fuse to be in order, check the relay by first detaching the Hall sender connector from the ignition system distributor.

4 Remove the fusebox and relay plate cover then pull free the pump relay from position 2.

5 Using a voltmeter, switch on the ignition and check the voltage reading between the following:
a) Contact No. 2 and earth b) Contact Nos. 2 and 1
c) Contact Nos. 4 and 1
d) Contact Nos. 5 and 1
6 In each case, battery voltage should show.

7 Check that when the central connector wire is earthed briefly, there is a voltage drop. If the voltage does not drop, check the ignition (TCI/H switch) unit. If the voltage does drop, renew the fuel pump relay. If the problem still persists, have the ignition Hall sender unit checked.

Removal
8 If after making the above checks the pump still malfunctions, remove the sender unit as described in Part A of this Chapter, Section 8, then detach the pump for renewal.

Refitting
9 Refitting is a reversal of the removal procedure.