740 L4-2.3L SOHC VIN 88 B230F (1985)
Meter should show 0 to 2.6 volts depending on CO-screw position.
0 volts =
max. lean position
2.6 volts = max. rich position
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Turn screw on air mass meter and check if voltage changes.
If no voltage or no variation when screw is turned, check wiring continuity.
NOTE:
Adjustment screw must be resealed after adjustment.
Check air mass meter output
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Turn ignition ON.
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Connect a voltmeter between terminal 7 at the LH control unit and ground.
Meter should show 1.2 volts.
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Start engine and warm up to operating temperature (AC off).
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Check output at idle (750 rpm). Meter should show 2.2 volts.
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Increase engine speed to 3,500 rpm. Output should increase to 2.9 volts. Check wiring continuity if out of specification.
Burn off function
Engine running at operating temperature.
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Connect a volt meter between terminal 4 and ground.