Topaz V6-182 3.0L (1992)
Idle Speed: Adjustments
NOTE: The curb and fast idle speeds are controlled by the EEC-IV processor and the Idle Air Bypass Valve assembly. The Idle Air Bypass Valve
assembly is not adjustable. A large increase or decrease in closed plate airflow from the calibrated level will not allow this device to control the speed.
To reflect the expanded application of the Self-Test idle speed options, the idle speed setting procedure has been revised considerably.
Throttle Body Description
As part of the sludge tolerant design, the throttle body incorporates an orifice in the throttle plate to control idle airflow. Throttle bodies with sludge
tolerant design are identified with a Yellow/Black decal, warning that the throttle plate stop screw must not be adjusted counterclockwise (backed off).
This will not reduce the engine speed but may cause the throttle plate to stick in the bore. Backing out the screw may be required if the throttle body has
been previously serviced (a plug in the throttle plate orifice may be present), or the plate stop screw tampered with (TPS Self-Test output out of range).
The decal also warns that the throttle body must NOT be cleaned inside the bore, as this cleaning will impair the sensitive coating. The sludge
accumulation will not affect the idle air flow. The cleaning procedure for the Idle Air Bypass Valve still applies.
REMEMBER
A change in idle airflow can occur not only at the throttle body but other areas as well. You should enter the idle speed procedure only after other
possible causes in the following areas are eliminated.
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Contamination within the idle speed control device
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Lack of fuel system control (excessively rich or lean)
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Throttle sticking or binding
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Engine not reaching operating temperature
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Incorrect ignition timing
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Incorrect or clogged PCV system
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Vacuum leaks (intake manifold, vacuum hoses, vacuum reservoirs, power brake booster etc.
VERIFY
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Transmission is in PARK (A/T), or NEUTRAL (M/T)
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Parking brake is applied (automatic brake release disconnected where applicable)
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Wheels blocked
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Engine at operating temperature
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Proper fuel pressure and no exhaust smoke
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Correct and clean PCV system
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Heater, A/C, and other accessories OFF
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Ignition timing is set to specification
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EEC-IV diagnostics have been performed and vehicle malfunction indicated service output codes have been resolved.
PROCEDURE - STAR TESTER OR EQUIVALENT SCANNER REQUIRED
STEP 1
Activate engine running Self-Test.
STEP 2
After service code 11 or 111 has been displayed, unlatch and within 4 seconds latch the STI button.
STEP 3
A single pulse code indicates the entry mode, then observe the Self-Test Output (STO) of the STAR tester in Step 4. If adjustment is required in Step
