Checking the idle speed and CO content (BMW 3 Series E30)

Please note: When the Motronic system is installed, the idle speed is controlled electronically and cannot be adjusted.

L-/LE-Jetronic

Connect the devices for measuring the number of revolutions and CO content in accordance with their operating instructions.

Warm up the engine to operating temperature. Oil temperature should be at least 60°C.

Check the ignition timing (see section "Checking and adjusting the ignition timing").

Check the tightness of the intake system. To do this, use a brush to wet all the joints of the intake device with gasoline. If you briefly increase the engine speed, air will be sucked in at the places of loose contact. Localize and eliminate leaks.

Warning: Do not inhale fuel vapors - poison! Do not allow gasoline to splash onto hot parts or the ignition system. Fire hazard!

Check the air filter element.

Turn off all electrical consumers.

Disconnect the crankcase ventilation hose from the cylinder head cover and route it so that only outside air can be sucked in.

Check the engine idle speed. For the specified value, see the table in the "Ignition System" section. If there are any deviations, adjust the idle speed with the adjusting screw at the throttle stop.

Check the CO content. For the specified value, see the table in the "Ignition system" section.



If the CO content deviates from the specified value, remove the seal from the CO content adjustment screw on the air flow meter.



Disconnect the hose from the throttle valve branch pipe that goes to the container with activated carbon and close the hose and fitting with plugs.



Adjust the set value of the CO content by turning the adjusting screw (arrow). This requires a 5 mm Allen key, such as the HAZET 2100-5. Turning it clockwise increases the CO content, and turning it counterclockwise decreases it.

After completing the adjustment, install a new seal.

Check the enrichment mode at partial loads. To do this, disconnect and plug the vacuum hose from the discharge valve. The CO content should increase significantly to approximately 2.5%. Then reconnect the hose.

Turn off the measuring instruments.

Connect the engine crankcase ventilation hose.

Adjusting the throttle cable

Caution: The gas cable is sensitive to bending and requires special care when installing. Even a slight bend can cause it to break later. Therefore, it is prohibited to install cables with bends.

Press the gas pedal all the way down (full throttle position) and fix it in this position with a suitable board inserted between the pedal and the seat.



Press the throttle lever "2" to the full throttle position and screw in the adjusting nut "1" until the throttle cable is tensioned.



Disconnecting the throttle cable from the throttle lever

Apply gas with throttle lever "2" to relieve the throttle cable nipple.

Compress the clamp "3" and push it away from the throttle lever.

Disconnect the throttle cable through the slot on the throttle lever.

Pull the cable sheath "5" out of the rubber tip "4", use a screwdriver to press the rubber tip out of the holder and pull the cable out through the slot in the holder.

Connection

Insert the gas cable through the slot into the hole in the throttle lever, install and press the bracket.

Apply a little gas with the throttle lever, insert the cable into the hole in the holder, press the rubber tip and insert the cable sheath into it.

Check the throttle cable adjustment.

Checking the performance of the fuel pump

Connect a voltmeter to the fuel pump.

Disconnect the fuel pump relay.

Short-circuit terminals -87b- and "30" on the multi-pin connector, the pump should start working, and the voltage on the pump should be at least 11.5 V. Otherwise, check the battery, wiring and connection points.

Connect an ammeter between terminals -87b- and "30" on the multi-pin connector. The fuel pump consumption must not exceed the following values:

• 318i cars with K-Jetronic: 9.5 A;
• cars with L-Jetronic OME produced before August 1985: 6.5 A;
• released since September 1985: 5 A.

Disconnect the fuel supply hose from the pressure regulator and lower the hose into a measuring cup with a capacity of about 3 liters.

Jumper terminals -87b- and "30" on the multi-pin connector and let the fuel pump run for about 30 seconds. Amount of fuel pumped out:

• 318i cars with L-Jetronic, 320i: 700 cm³;
• 325e, 325i: 850 cm³.

If the fuel pump performance is lower, replace the fuel filter and check the performance again. If the performance is still insufficient, replace the fuel pump.