TYHJÄKÄYNTI

[jtammel]

Tässä ohjeet kuinka puhdistaa IAC ja säätää tyhjäkäynti:

How to Service the Idle Air Control (IAC)

Background
1. The IAC is used by the ECM to create a controlled air "leak" that establishes the idle
speed.
2. Problems with the IAC can result in hunting idle, stalling and poor tip-in.

Cleaning/Replacement
The IAC pintel and bore should be periodically cleaned to remove carbon from the EGR feedback residues. The IAC bore in the base plate should be cleaned before installing a new IAC assembly (skip steps 3 & 4).
1. Disconnect the cable from the IAC motor.
2. Unscrew the IAC motor from the base using care not to lose the pintel and spring.
3. Remove the IAC gasket and use TB cleaner to clean carbon from the IAC pintel.
4. Clean the IAC pintel bore within the base. Use care not to leave any debris within
the bore.
5. Install the pintel and spring back into the IAC motor, if it fell out.
6. Install thegasket onto the IAC motor and screw the assembly back into the base.
7. Install the cable into the IAC connector.

Pre-Adjustment Setup
1. Jumper ALDL pins A & B (upper right) together.
2. Turn the ignition key On.
3. Wait 1 minute for the ECM to fully extend the IAC pintel
4. Disconnect the cable from the IAC motor so the pintel will remain extendd.

Base Idle Adjustment
The base idle adjustment screw is located on the driver side of the TB.
1. Start the engine and set base idle to 450RPM. This is best done by starting
at a higher idle and slowly backing down in RPM.
2. Stop the engine, reconnect the cable to the IAC motor and remove the ALDL
pins A & B jumper.
3. Restart the engine and verify idle speed control is working properly.
NOTE If idle problems persist, replacement of the IAC motor/pintel may be required.



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1988 Corvette