Mixture Control Unit-Checking

MIXTURE CONTROL UNIT - CHECKING





Both the air sensor plate and the control plunger must move freely to ensure accurate control of the air/fuel mixture.
Run the fuel pump for a few seconds:
This insures that residual control pressure pushes the control plunger against the sensor lever.
Turn off ignition.
Remove Rubber Connecting Boot.
Lift Sensor Plate:
Use a strong magnet or small pliers - the plate should move in both directions without "hanging up."
If the plate hangs up in both directions, the problem can usually be corrected by centering the sensor plate or lever (see air sensor - checking and adjusting).





If the plate hangs up on upward movement:
Remove the fuel distributor from the air sensor housing.
Check the control plunger for free movement:
Be careful not to drop the plunger.
Rinse the control plunger in clean solvent:
If the plunger still hangs up, the fuel distributor must be replaced since the plunger cannot be repaired or replaced separately.
Install plunger with small shoulder first:
Lubricate the plunger with gasoline, make sure O-ring is properly seated.