Checking the power supply
Check the fuel pump fuse. K-Jetronic: fuse #13, KE-Jetromc: fuse #13 and 24.
Disconnect the high voltage wire - terminal 4 on the ignition distributor (central cable) and short it to ground, if necessary, use an auxiliary cable with the same cross-section.
Turn on the starter for a short time, the fuel pump should start working (make noise).
Otherwise, connect auxiliary control.
Press the auxiliary control button. If the fuel pump now starts, check the fuel pump relay.
Otherwise, unscrew the fuel pump electrical wires and connect the voltage indicator. Press the remote control button, the LED should light up, otherwise determine the location of the wire break according to the diagram and fix the problem.
If voltage is present, replace the fuel pump.
Connect the electrical wire to the fuel pump.
Performance Check
Connect the voltmeter to the fuel pump. Press the auxiliary control button, read the voltage readings and record them as value X.
To relieve pressure, remove the gas cap for a short time.
Disconnect the fuel return line and place it in a measuring vessel.
Turn on the pump for 30 seconds and measure the volume of fuel.
Coupe
Limousine (Sedan)
For the recorded value of voltage X, determine the minimum permissible capacity Y from the diagram. Example: The value of voltage X = 10.2 V corresponds to the feed volume Y = 505 cm³.
Compare the minimum acceptable performance with the actual measured performance.
Caution: If the voltage is normal but the output is too low, replace the fuel pump.
Check the high voltage wire to the ignition distributor.
Checking the fuel pump relay
The fuel pump relay should be checked if the fuel pump does not operate.
Remove the fuel pump relay (socket no. 10).
K-Jetronic and 90hp engine with KE-Jetronic
Disconnect the Hall sensor connector on the ignition distributor by pressing the wire clip.
Turn on the ignition v measure the voltage between the following contacts: 48 and ground; 48 and 50; 46 and 50. Should be: 12 V (battery voltage). If necessary, find the wire break according to the diagram and fix the problem.
Connect a voltmeter between contacts 51 and 50. There should be battery voltage (12 V).
Momentarily short-circuit the center wire on the Hall sensor connector to ground using an auxiliary wire. The voltage should drop briefly. In this case, replace the fuel pump relay or check the Hall sensor/TSZ-H switch.
Otherwise, find and fix the wire break according to the diagram
Engines 113, 115, 136 hp. with KE-Jetronic
Turn on the ignition and check the voltage between the following contacts: 48 and ground, 46 and ground. The LED of the tester should light up. If necessary, find and fix the wire break according to the diagram.
Turn off the ignition.
Connect the voltage tester between contacts 46 and 47.
Turn on the ignition. The LED should light for 1 second.
Otherwise, use the diagram to find the break in the wire to the VEZ control device and fix the problem.
[Material republished from the website: AudiManual]