The wiper and flap tension mechanism are located under the rectangular plastic cover (approx 2.5 by 3.5 inches) on the top of the airflow meter. The airflow meter is a precision mechanical balance and is sealed for life at the factory - the plastic cover should never be removed. The mechanism should NEVER be adjusted or lubricated or cleaned - it is meant to look as if the wiper arms have scored the carbon tracks! Idle mixture adjustment is via sunken hex head screw in body of airflow meter.
If this cover is loose it has been removed. Do not mistake factory resin sealer beads for evidence that cover has been forced off - look for scratches and/or loose cover. If there is no evidence cover has been removed LEAVE IT ALONE and do not attempt spring adjustment - IT IS NOT WORTH THE PROBLEMS SPRING TENSION ADJUSTMENT WILL CAUSE!
Also - Please be aware that airflow meters from vehicles fitted with LPG gas may have suffered from blowback damage which may make any mixture adjustment ineffective. ALWAYS ask owners of LPG vehicles if they have had blowback problems. If the flap sticks or feels rough when moving by hand it is probably beyond repair and should be replaced.
If the airflow meter has been opened AND 'adjusted' in an attempt to overcome running problems caused by ECU failure, it MAY be necessary to re-adjust the spring tension after the ECU problems have been rectified. ALWAYS ROAD TEST WITH YOUR REBUILT ECU - there may be no need to re-adjust airflow meter! If car runs fine and CO is adjustable then airflow meter should be OK.
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