E7C Checking and Adjusting the CO Content
E7C Checking and adjusting the CO content1 Connect the CO meter, exhaust extraction equipment and tachometer.
2 Start the engine and warm it up. Check the CO content, (1% to 2%)
If the CO content is not to specification, turn the adjusting screw:
clockwise - if it is too low
anticlockwise-if it is too high.
3 If the CO content is higher than 6%and cannot therefore be adjusted, switch off the engine. Unplug the mass air flow sensor connector and connect the multimeter across pins 3 and 6 of the mass air flow sensor.
Turn the adjusting screw as many turns as required to obtain a reading of 380 ohms.
If you cannot obtain this reading, fit a new mass air flow sensor. On obtaining the correct reading, 380 ohms, plug in the mass air flow sensor connector. Start the engine and warm it up. Check the CO content again arid adjust it further until it is exactly right. If the correct CO content still cannot be obtained, check the mass air flow sensor wiring and connections as described in point E7A.
4 If the wiring is OK and the CC content still cannot be adjusted, try a new control module.