Mixture Control Solenoid
NOTE:
Mixture control solenoid must be removed from carburetor to inspect and test.
- The rubber seal at lower end of solenoid must be free of any cuts, nicks or cracks. Also the rubber seal must not be shrunk of hardened. A new rubber seal and retainer should be installed.
- Install spacer and new seal on mixture control solenoid stem, making sure seal is up against spacer. Using a 3/16" socket and light hammer, carefully drive new retainer on stem, so that there is a slight clearance between the retainer and the seal to allow for seal expansion.
- The mixture control solenoid can be checked for a sticking plunger or a leaking fuel valve. With mixture control solenoid removed, connect electrical connector (harness on vehicle) with solenoid removed from carburetor.
- Ground dwell terminal (Green connector). Connect vacuum pump to end of solenoid. Select rubber hose that will snugly fit over rubber seal. With ignition on and engine stopped, this energizes solenoid (lower end of plunger sealed).
- Apply approximately 10 in. Hg of vacuum (maximum) and hold. If vacuum won't hold for at least 5 seconds, replace solenoid. Disconnect ground from dwell lead and vacuum gauge reading should instantly go to zero. Replace solenoid if stuck in down position.
- If functional checks indicate a good mixture control solenoid but calibration problems continue, there will be concealed wear or damage to the fuel control end of the solenoid plunger. Replace solenoid assembly.