5000CS Turbo L5-2226cc 2.22L SOHC Turbo (MC) (1987)
Checking OXS-Duty Cycle (CO Value)
NOTE: Radiator fan must NOT be running while checking or adjusting
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disconnect VW 1367 test lead from terminal 1 of ignition coil, and connect it to oxygen sensor test connector (blue/white wire)
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disconnect inductive pick up from spark plug wire (no. 1 cylinder)
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remove TDC sensor from transmission housing
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depress "Dwell Angle %" button on VW 1367
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start engine and allow to idle
NOTE: Ignore the RPM display on the VW 1367 tester while performing this check
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observe oxygen sensor duty cycle
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specification : 25% to 65% fluctuating
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observe CO content on EPA 105
^
specification: 0.3 to 1.2% volume (with oxygen sensor connected)
If CO value exceeds 1.2% with OXS-duty cycle from 25 - 65%, then check for the following
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Ignition system not operating property
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Exhaust system leaking
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Fuel distributor improperly distributing fuel (check and repair any or all as necessary)
If OXS-duty cycle is less than 25% or exceeds 65%, than a CO adjustment is necessary. Proceed as follows:
Adjusting OXS-Duty Cycle (CO Value)
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switch ignition OFF
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remove air intake duct from air flow sensor
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center punch mixture adjusting screw plug
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drill 2.5 mm (3/32 in.) hole in center of plug 3.5 - 4.0 mm (9/64 - 5/32 in.) deep
CAUTION: Clean up any metal shavings. Apply grease to drill bit to catch shavings.
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screw 3 mm (1.8 in.) sheet-metal screw into drilled hole
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remove plug with screw, using pliers
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reinstall air intake duct
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raise above 2,000 RPM briefly then let engine idle