740 L4-2.3L SOHC VIN 88 B230F (1985)
Ground the green wire from the control unit (at the firewall).
The pointer on the MONOTESTER should move to:
B28F (CI) 70 degrees or above
B23FT, B230FT, B230F 0 degrees.
Reconnect the green wire to the Lambda sensor.
CO-Check & Adjustments; Enrichment Systems Information
CO-CHECK AND ADJUSTMENTS
Connect the lambda sensor.
Warm up the engine to normal operating temperature. Check that ignition timing and idle speed are within specification. Adjust when necessary.
Check the "dwell" reading on the MONOTESTER. The reading should not be stable. With the correct CO setting, the reading should fluctuate around
the following values:
B28F (CI)
43 degrees (41-44)
B23FT, B230FT, B230F (LH)
20-70 degrees
ADJUSTMENT
B28F (CI): A high reading indicates a lean mixture and the CO adjustment screw should be turned clockwise. A low reading indicates a rich mixture and
the CO adjustment screw should be turned counter-clockwise.
B23FT, B230FT, B230F (LH): A high reading indicates a rich mixture and the CO adjustment screw should be turned counter-clockwise. A low reading
indicates a lean mixture and the CO adjustment screw should be turned clockwise.
The adjustment range on LH-Engines is 15 turns on the CO adjustment screw. The range where the pointer fluctuates on LH engines is equivalent to one
turn on the CO adjustment screw.
NOTE:
The emission regulations in the U.S. and Canada require access to CO-adjustment be sealed. After adjustment, the CO-adjustment must be
resealed.
ENRICHMENT SYSTEMS, B28F (CI)
The CI-system for B28F is equipped with inter-related enrichment systems:
^
Cold start enrichment system
^
Acceleration enrichment system