BMW Coupes and Sedans 1970-1988 Repair Guide

Fuel Injection Systems

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KUGELFISCHER MECHANICAL SYSTEM



2002Tii Models

Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. Run the engine until it reaches normal operating temperature. Remove the cap from the top of the throttle butterfly port.
  2.  
  3. Adjust the idle speed by turning the idling speed screw to obtain an idle of 850-950 rpm.
  4.  
  5. With a CO meter attached to the exhaust pipe of the car, turn the throttle butterfly air adjustment screw to obtain a reading of 2.0-3.0% CO. Turning the screw in clockwise direction will lean the mixture, while turning counterclockwise will richen the mixture. Refer to the engine compartment sticker for idle and CO specifications.
  6.  
  7. With the vehicle still in NEUTRAL or PARK, apply throttle several times to increase the rpm, and check to see if the idle returns to normal. If necessary, readjust each screw until the CO reading and idle speed remain constant.
  8.  

ELECTRONIC SYSTEMS



320i Models

All 320i models are equipped with the Bosch® K-Jetronic continuous fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. Run the engine until it reaches normal operating temperature.
  2.  
  3. Adjust the engine idle speed. The adjustment screw is located near the throttle valve linkage.
  4.  
  5. Detach the exhaust check valve and plug the hose.
  6.  
  7. To adjust the CO, remove the plug from the fuel distributor with BMW special wrench. Adjust the CO level to a maximum of 2.0% for the 49 state vehicles or 3.5% for the California cars.
  8.  
  9. Reconnect the exhaust check valve hose and check the idle speed.
  10.  

530i Models

See Figure 1

All 530i models are equipped with the Bosch® L-Jetronic fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. Run the engine until it reaches normal operating temperature.
  2.  
  3. Disconnect the hose from the collector to the charcoal filter. Do not plug the line.
  4.  

The hose is located between the first and second air induction tubes.

  1. Disconnect the air pump hose at the air pump and plug the line.
  2.  
  3. Adjust the idle speed by turning the adjusting screw on the side of the throttle housing.
  4.  
  5. Turn the screw until the the CO level is between 1.5-3.0% at idle.
  6.  
  7. If necessary, adjust the CO with the idle air screw located on the air volume control.
  8.  
  9. Reconnect the hoses when complete.
  10.  



Click image to see an enlarged view

Fig. Fig. 1: Idle speed adjustment screw-530i models

528e Models

All 528e models are equipped with the Bosch® L-Jetronic fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. Pull the canister purge hose off the solenoid, leaving the connections unplugged.
  2.  
  3. Fasten the CO meter 13 0 070 or equivalent to the manifold using BMW nipple 13 0 100.
  4.  
  5. With the engine valve clearances correctly adjusted, ignition timing correct and the engine at normal operating temperature, measure the CO percentage at idle. the CO nominal value is 0.2-1.2%.
  6.  
  7. If the CO level is within the specified range, disconnect the test unit, replace the plug in the exhaust manifold, and conclude the test. If not, adjust the CO as described below:
    1. Turn OFF the engine and unplug the oxygen sensor. Remove the anti-tamper plug in the throttle body with special tool No. 13 1 092 or equivalent. Then screw the special extractor tool No. 13 1 094 or equivalent into the hole and draw the plug out with a slide hammer or suitable tool.
    2.  
    3. With the engine running and at normal operating temperature, use adjustment tool 13 1 060, 13 1 100 or equivalent to fine tune the CO level.
    4.  
    5. When the adjustment is complete, install a new anti-tamper plug, and reconnect the oxygen sensor plug and the carbon canister hose. Also, remove the nipple in the exhaust manifold and replace the plug.
    6.  
    7. Reinstall the exhaust manifold bolts.
    8.  

  8.  

528i Models

See Figure 2

All 528i models are equipped with the Bosch® L-Jetronic fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. Adjust the idle speed if needed. The idle screw is on the side of the throttle body housing. Turning it clockwise will decrease the idle and counterclockwise will increase it.
  2.  
  3. Remove the CO test plug at the rear of the exhaust manifold and connect a CO meter. Start the engine and run it until operating temperature is reached, if not unready done. Measure the CO reading and adjust to 0.2-0.8% CO.
  4.  
  5. Unfasten the connector for the oxygen sensor on the right side of the firewall in the engine compartment. When disconnected, the CO valve should not change.
  6.  
  7. If CO is not to specification, adjust the mixture by turning the adjusting screw, located low on the airflow meter. Adjust for 0.5% CO.
  8.  
  9. Reconnect the oxygen sensor and check CO again. If CO does not meet specification, the vehicle should be taken to a professionally trained injection system specialist.
  10.  
  11. When complete, disconnect the test probe and reinstall the test plug into the exhaust manifold.
  12.  
  13. Recheck the idle speed.
  14.  



Click image to see an enlarged view

Fig. Fig. 2: Idle adjustment screw-528i models

318i Models

See Figures 3, 4 and 5

All 318i models are equipped with the Bosch® L-Jetronic fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. The engine must be run until it is at normal operating temperature. Ignition timing and valve clearances must be to specification. Connect the BMW digital mixture measurement tool 12 6 400 or equivalent according to the instrument instructions. Disconnect the hose going to the active carbon filter on the throttle housing. Do not plug the open connections.
  2.  
  3. Operate the engine at 3000 rpm for 30 seconds to ensure that the oxygen sensor is at operating temperature.
  4.  



Click image to see an enlarged view

Fig. Fig. 3: Anti-tamper plug in the air filter assembly



Click image to see an enlarged view

Fig. Fig. 4: Removing the anti-tamper plug

  1. Disconnect the oxygen sensor wire, and fasten it where it cannot touch a ground. Read the display on the gauge and note the reading. This reading will be the nominal value.
  2.  
  3. Reconnect the oxygen sensor into the test unit. The actual value will appear in the display. If the actual value is within 0.3 volts of the original value, the CO is within tolerance. If not, proceed as follows.
  4.  

Several special tools are required to remove the anti-tamper plug for the adjustment screw and to turn the adjustment screw. Get a new anti-tamper plug before beginning work.

  1. Use special tool 13 1 092 or equivalent to remove the anti-tamper plug. If you do not have access to the correct tool, the plug can be removed by drilling it out.
  2.  
  3. When the anti-taper plug is removed,. Then screw special tool 13 1 094 or equivalent into the plug, and use the slide hammer on the tool to draw the plug out.
  4.  
  5. Use a special tool 13 1 060 to turn the adjusting screw to bring the actual valve to within 0.3 volt of the nominal value. Turn OFF the engine, then disconnect the test unit and reconnect the oxygen sensor wire to the oxygen sensor. Replace the anti-tamper plug with a new one.
  6.  



Click image to see an enlarged view

Fig. Fig. 5: Special tool installed to adjust the CO level

325, 325e, 325i, 325iS and 325iX Models

All 325, 325e, 325i, 325iS and 325iX models are equipped with the Bosch® L-Jetronic fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. Disconnect the hose leading from the throttle housing to the carbon canister. Do not plug the openings.
  2.  
  3. Remove the bolts on either side of the exhaust manifold plug.
  4.  
  5. Remove the plug in the exhaust manifold and install test nipple 13 0 100 or equivalent and connect the CO tester 13 0 070 or equivalent into the open nipple.
  6.  
  7. With the engine valve clearances correctly adjusted, ignition timing correct and the engine at normal operating temperature, measure the CO percentage at idle. the CO nominal value is 0.2-1.2%.
  8.  
  9. If the CO level is within the specified range, disconnect the test unit, replace the plug in the exhaust manifold, and conclude the test. If not, adjust the CO as described below:
    1. Turn OFF the engine and unplug the oxygen sensor. Remove the anti-tamper plug in the throttle body with special tool No. 13 1 092 or equivalent. Then screw the special extractor tool No. 13 1 094 or equivalent into the hole and draw the plug out with a slide hammer or suitable tool.
    2.  
    3. With the engine running and at normal operating temperature, use adjustment tool 13 1 060, 13 1 100 or equivalent to fine tune the CO level.
    4.  
    5. When the adjustment is complete, install a new anti-tamper plug, and reconnect the oxygen sensor plug and the carbon canister hose. Also, remove the nipple in the exhaust manifold and replace the plug.
    6.  
    7. Reinstall the exhaust manifold bolts.
    8.  

  10.  

633CSi and 733i Models
1982 VEHICLES

All 1982 633CSi and 733i models are equipped with the Bosch® L-Jetronic fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. Run the engine until at normal operating temperature.
  2.  
  3. Disconnect the throttle housing-to-activated carbon filter hose. Unfasten and plug the air hose at the air pump.
  4.  
  5. Adjust the idle speed, if needed using the idle adjusting screw, located in the side of the throttle housing.
  6.  
  7. Adjust the CO to 1.5-3.0% at idle. If adjustment is needed, remove the cap from the air flow sensor and use either the BMW adjustment tool, or a short screwdriver, turn the bypass air screw located in the air flow sensor.
  8.  
  9. When complete, reconnect the hoses.
  10.  

533i, 535i, 633CSi, 635CSi,733i and 735i Models
1983-88 VEHICLES

All 1983-88 533i, 535i, 633CSi, 733i and 735i models are equipped with the Bosch® L-Jetronic fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. Check and adjust the idle speed, if needed, to specification.
  2.  
  3. Disconnect the evaporative canister purge hose at the bottom of the solenoid mounted on the firewall. Leave the openings unplugged.
  4.  
  5. Unscrew the bolts on the exhaust manifold and install a BMW nipple No. 13 0 100 or equivalent, then connect the CO test unit 13 0 070 or equivalent. Check to see if the CO level is between 0.2-1.2%. If the CO is not within limits, adjust it as followed:
    1. Turn off the engine and unplug the oxygen sensor plug.
    2.  
    3. Remove the air flow sensor by unfastening the air cleaner and remove the 3 mounting bolts to separate the airflow sensor.
    4.  
    5. Use special tool 13 1 092 or equivalent to remove the anti-tamper plug. Use tool 13 1 094 or equivalent and slide hammer the remaining plug.
    6.  
    7. Once the plug is removed, install the air flow sensor back onto the air cleaner and reinstall the air cleaner. With the engine at normal operating temperature and the oxygen sensor plug still disconnected, measure the CO and adjust it with Tool 13 1 060 or 13 1 100 or equivalent. The CO level should meet the nominal value of 0.2-1.2%.
    8.  
    9. Once the level is adjusted, stop the engine and reconnect the oxygen sensor plug. Then, remove the air flow sensor, put it on a bench, and install a new anti-tamper plug. Reinstall the airflow sensor and air cleaner. Reconnect the canister purge hose to the solenoid.
    10.  

  6.  

M5 and M6 Models

See Figure 6

All M5 and M6 models are equipped with the Bosch® L-Jetronic fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

  1. Make sure the engine is at normal operating temperature, and that the air cleaner is in reasonably clean condition. All basic engine tuning factors (spark plug condition and gap, valve adjustment, ignition timing, etc.) must be correct.
  2.  



Click image to see an enlarged view

Fig. Fig. 6: To adjust the idle speed, turn the screw (1) in small increments

  1. Adjust the idle speed by turning the screw shown in the illustration.
  2.  
  3. To adjust CO, remove the cap located at the center of the top surface of the airflow sensor. Use special tool 13 1 100 to turn the airflow control screw in the airflow sensor. To access this the anti-tamper cap must be removed.
  4.  
  5. Adjust the CO content until CO is between 0.4-1.2%.
  6.  
  7. Install a new cap when CO meets specification.
  8.  

M3 Models

All M3 models are equipped with the Bosch® L-Jetronic fuel injection system.


CAUTION
Before checking or adjusting the engine idle, make sure the vehicle is in a well ventilated area, and the transmission is in NEUTRAL or PARK with the wheels securely blocked for your protection.

This test must be performed at essentially sea level altitude. In an area well above sea level, it will be necessary to use a BMW Service Tester (or equivalent device from another source) and run the test with the system's altitude correction box connected.

  1. Make sure the engine is at operating temperature, and that the air cleaner is clean. All basic engine tuning factors (spark plug condition and gap, valve adjustment, ignition timing, etc.) must be correct.
  2.  
  3. Make sure all accessories are OFF .
  4.  
  5. A special electrical fitting (BMW special tool 13 4 010 or equivalent) is required to disable the Motronic control system's throttle valve switch. Pull off the electrical connector leading to the throttle valve switch. Then, plug the special tool into the open end of the connector.
  6.  
  7. Adjust the idle speed to specification by turning the screw located just above the M on the valve cover. Make sure to restore the throttle valve switch when the idle speed is correct.
  8.  
  9. To adjust CO, remove the cap located at the center of the top surface of the airflow sensor. Use special tool 13 1 100 to turn the airflow control screw in the airflow sensor. To access this the anti-tamper cap must be removed.
  10.  
  11. Adjust the CO content until CO is between 0.4-1.2%.
  12.  
  13. Install a new cap when CO meets specification.
  14.  

 
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