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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 23 (Engine Controls - Adjustments - 2.5L) >> Adjustments >> Throttle Body Minimum Airflow

Throttle Body Minimum Airflow

WARNING: This page is about a different car, the 1995 Plymouth Voyager, 1995 Plymouth Grand Voyager, 1995 Dodge Grand Caravan, 1995 Dodge Dakota, and 1995 Dodge Caravan. However, it is still accessible from the selected car via links, so may be relevant.
  1. Set parking brake and block front wheels. Warm engine in Park or Neutral until cooling fan cycles on and off at least once. Ensure all accessories are off. remove air cleaner assembly and plug heated air door vacuum hose. Connect timing light and tachometer. Disconnect engine coolant temperature sensor. Set basic timing to specification. See IGNITION TIMING  table under IGNITION TIMING. Turn engine off. Reconnect coolant temperature sensor.
  2. Disconnect PCV hose from intake manifold. Attach Air Metering Fitting (6457) to intake manifold PCV nipple.
  3. Disconnect idle purge hose from vacuum harness "T". Attach Air Metering Fitting (6457) to the intake manifold-mount ed idle purge hose. Orifice size is .125" (3 mm).
  4. Connect DRB to DLC. Start engine and allow to idle for at least one minute. Ensure no vacuum leaks exist. Using DRB, access MINIMUM AIRFLOW IDLE SPEED. When accessed, IAC motor will fully close, spark advance will become fixed, fuel delivery will not change, and engine RPM will be displayed on DRB.
  5. Check engine idle speed on tachometer. See THROTTLE BODY MINIMUM AIRFLOW IDLE SPECIFICATIONS table. If throttle body minimum airflow idle speed is not within specification, remove throttle body from engine. While holding throttle open, spray throttle body bore and manifold side of throttle with Mopar Parts Cleaner. Using a soft scuff pad, clean top and bottom of throttle body bore and edges, and manifold side of throttle blade.
  6. Dry throttle body with compressed air and inspect for foreign material. Install throttle body to engine and retest throttle body minimum airflow idle speed. If minimum airflow idle speed is not within specification, replace throttle body.
THROTTLE BODY MINIMUM AIRFLOW IDLE SPECIFICATIONS

Application RPM
Caravan & Voyager 800-1200
Dakota 1050-1250