Vanagon F4-1970cc 2.0L (1982)
Distributor Advance Unit: Testing and Inspection
California
With Siemens 451 Tester or Equivalent
Ignition distributor, checking centrifugal advance with SIEMENS 451 tester or equivalent
Work sequence
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connect tester according to manufacturer's instructions
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remove idle stabilizer plugs and connect together
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start engine and run at idle
ignition timing and rpm will register directly on tester
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adjust idle speed
manual: 850 - 950 rpm
automatic: 850 - 950 rpm
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check and adjust ignition timing if necessary
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pull off both vacuum hoses from distributor vacuum unit
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plug vacuum retard hose
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reset idle speed to specifications
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note advance angle on tester (basic advance angle)
Note: Start of centrifugal advance is shown by increasing advance angle registered on tester while increasing rpm
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increase engine speed slowly to 1600 rpm
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read off advance angle on tester
Note: To determine centrifugal advance, subtract basic advance angle from last advance angle measured
Example: last advance angle measured (-) minus basic advance angle (=) centrifugal advance
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compare centrifugal advance angle to specified value on specifications chart
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repeat test at 3400 rpm
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reconnect vacuum hoses when test completed
Note: With vacuum hoses connected, adjust idle speed to given specifications before connecting plugs to idle stabilizer
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reconnect idle stabilizer
With Timing Advance Tester
Ignition distributor, checking centrifugal advance with timing advance tester
Work sequence
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connect tester according to manufacturer's instructions
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pull advance and retard hoses off vacuum unit
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disconnect plugs from idle stabilizer and connect together
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start engine and adjust idle speed to 900 rpm