740 L4-2.3L SOHC VIN 88 B230F (1985)
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Adjust engine speed with idle adjustment screw to 700 rpm.
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Disconnect ground from test point.
Engine speed should increase to 750±20 rpm
If values are incorrect: check/adjust Throttle Body and/or Throttle Cable/Linkage.
Check/Adjust Ignition Setting
Idle speed fluctuations can affect ignition setting. Make sure that fluctuations are not greater than 25 rpm.
If greater, check air control valve hoses for blockages.
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Check ignition timing with stroboscope.
Ignition setting should be 12° BTDC at idle.
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Adjust setting by turning distributor body.
Check CO
Fig. 342 CHECK AND ADJUST CO
Test diode should flash if CO is correct.
If test diode remains ON = CO is too high (rich air/fuel mixture).
If test diode remains OFF = CO is too low (lean air/fuel mixture).
Adjusting CO
CO should only be adjusted after all possible faults have been checked/rectified.
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Turn off engine.