Operation check, removal and installation of the L-Jetronic air flow meter
Inspection (L-Jetronic systems)
1. Disconnect from the inlet fitting of the air flow meter. Carefully open and close the sensor flap and check for seizure. The flap during backflashes can bend and this leads to incorrect resistance measurements. The damper can bend and remain in the partially open position, causing the mixture to enrich and stop the engine at idle.
2. Disconnect the electrical connector from the air flow meter.
3. Check the resistance between contacts 7 and 8 with an ohmmeter. The resistance must constantly increase (without “flat sections”) when the sensor flap moves slowly from completely closed to fully open.
4. Also check the intake air temperature sensor (inside the flow meter). Check by ohmmeter the correctness of the resistance between pins 8 and 9 (see illustration above). The resistance at 20 ° C should be between 2200 and 2700 ohms.
5. If the resistance values ​​are correct, check the cables. Connect the connector to the flow meter. Check that the ignition is switched off. Disconnect the connector from the ECU (located under the dashboard on the right) and check the resistance between contacts 7 and 8 with an ohmmeter. Carefully remove the cover from the flow meter and observe the resistance change when moving from the closed position to the fully open position. The result of the check should be the same as the previous check. If there are any differences in the results, the cable may have breaks or short circuits.
Removal and installation
1. Disconnect the electrical connector from the flow meter.
2. Remove the air cleaner.
3. Unscrew the nuts and remove the flow meter from the engine compartment or from the air cleaner.
4. Installation is the reverse of removal.