Engine Controls - Adjustments Plymouth Acclaim I

ENGINE MECHANICAL

Before performing any on-vehicle adjustments to fuel or ignition systems, ensure engine mechanical condition is okay.

VALVE CLEARANCE

Note. Hydraulic lifters are used. No adjustments are required.

4-CYLINDER IGNITION TIMING

Note. Ignition timing on 2.2L turbo engine is computer controlled and is not adjustable.

2.2L TBI, 2.5L TBI & 2.5L Turbo

1. Place gear selector in Neutral or Park position. Turn off all lights and accessories. Connect inductive pick-up timing light to No. 1 cylinder.
2. Start and warm engine to normal operating temperature. Disconnect engine coolant sensor lead wire. Radiator fan should come on, and CHECK ENGINE light on instrument panel should illuminate.
3. Check timing through timing window in bellhousing. If timing is within 2 degrees of specification, DO NOT adjust ignition timing. See 4-CYLINDER IGNITION TIMING table. If timing is not as specified, loosen distributor hold-down bolt, and turn distributor housing until specified timing is obtained.
4. Recheck timing after distributor hold-down bolt has been tightened. Reconnect coolant lead wire. Erase fault codes. Remove diagnostic equipment.

4-CYLINDER IGNITION TIMING

V6 IGNITION TIMING

Note. Ignition timing on 3.3L and 3.8L engines is computer controlled and is not adjustable.

3.0L

1. Place gear selector in Neutral or Park position. Turn off all lights and accessories. Connect inductive pick-up timing light to No. 1 cylinder.
2. Start and warm engine to normal operating temperature. Disconnect engine coolant sensor lead wire. Radiator fan should come on, and CHECK ENGINE light on instrument panel should illuminate.
3. Check timing at crankshaft pulley. If timing is within 2 degrees of specification, DO NOT adjust ignition timing. See V6 IGNITION TIMING table. If timing is not as specified, loosen distributor hold-down bolt, and turn distributor housing until specified timing is obtained.
4. Recheck timing after distributor hold-down bolt has been tightened. Reconnect coolant lead wire. Erase any fault codes. Remove diagnostic equipment.

V6 IGNITION TIMING

IDLE SPEED & MIXTURE

Note. Mixture adjustment is NOT a part of normal tune-up procedure and should not be performed unless mixture control unit is replaced or vehicle fails emission testing.

Minimum Airflow Rate (2.2L TBI & 2.5L TBI)

1. Connect Diagnostic Readout Box II (DRB-II) to vehicle. Remove air cleaner assembly. Disconnect and plug heated air door vacuum hose. Ensure engine is at operating temperature (cooling fan cycles on and off at least once).
2. Connect timing light and tachometer to engine. Disconnect engine coolant temperature sensor. Ensure ignition timing is to specification. See 4-CYLINDER IGNITION TIMING under IGNITION TIMING. Turn engine off, and reconnect coolant temperature sensor.
3. Disconnect PCV hose from intake manifold. Attach Air Metering Fitting (6457) to manifold. Orifice size is .125" (3 mm). Start engine and allow it to idle for at least one minute.
4. Using DRB-II, access MINIMUM AIRFLOW IDLE SPEED. The AIS motor should fully close, fuel delivery should not change, and idle spark advance should be fixed. Ensure proper RPM is displayed on DRB-II.
5. Check idle RPM (minimum airflow rate) with tachometer. See 4-CYLINDER MINIMUM AIRFLOW RATE SPECIFICATIONS table. If minimum airflow rate is not to specification, replace throttle body. If minimum airflow rate is correct, turn engine off, and disconnect all test equipment.

4-CYLINDER MINIMUM AIRFLOW RATE SPECIFICATIONS

Minimum Airflow Rate (2.2L Turbo)

1. Ensure engine is at operating temperature (cooling fan cycles on and off at least once). Turn engine off. Connect tachometer to engine.
2. Disconnect PCV hose from intake manifold. Attach Air Metering Fitting (6457) to manifold. Orifice size is .125" (3 mm). Disconnect 3/16" manifold vacuum (idle) purge hose from top of throttle body. Plug3/16" throttle body nipple. Connect Diagnostic Readout Box II (DRB-II) to vehicle. Start engine and allow it to idle for at least one minute.
3. Using DRB-II, access MINIMUM AIRFLOW IDLE SPEED. The AIS motor should fully close, and idle spark advance should be fixed. Ensure proper RPM is displayed on DRB-II.
4. Check idle RPM (minimum airflow rate) with tachometer. See 4-CYLINDER MINIMUM AIRFLOW RATE SPECIFICATIONS table. If minimum airflow rate is not to specification, replace throttle body. If minimum airflow rate is correct, turn engine off, and disconnect all test equipment.

Minimum Airflow Rate (2.5L Turbo)

1. Ensure engine is at operating temperature (cooling fan cycles on and off at least once). Connect timing light and tachometer to engine. Disconnect engine coolant temperature sensor. Ensure ignition timing is to specification. See 4-CYLINDER IGNITION TIMING under IGNITION TIMING.
2. Turn engine off. Disconnect PCV hose from intake manifold. Attach Air Metering Fitting (6457) to manifold. Orifice size is .125" (3 mm). Disconnect 3/16" manifold vacuum (idle) purge hose from top of throttle body. Plug 3/16" throttle body nipple. Connect Diagnostic Readout Box II (DRB-II) to vehicle. Start engine and allow it to idle for at least one minute.
3. Using DRB-II, access MINIMUM AIRFLOW IDLE SPEED. The AIS motor should fully close, and idle spark advance should be fixed. Ensure proper RPM is displayed on DRB-II.
4. Check idle RPM (minimum airflow rate) with tachometer. See 4-CYLINDER MINIMUM AIRFLOW RATE SPECIFICATIONS table. If minimum airflow rate is not to specification, replace throttle body. If minimum airflow rate is correct, turn engine off, and disconnect all test equipment.

Minimum Airflow Rate (3.0L)

1. Ensure engine is at operating temperature. Turn off all lights and accessories. Connect timing light and tachometer to engine. Disconnect engine coolant temperature sensor. Ensure ignition timing is to specification. See V6 IGNITION TIMING under IGNITION TIMING. Turn engine off, and reconnect coolant temperature sensor.
2. With engine off, disconnect hose from PCV valve, and plug PCV valve nipple. Disconnect idle purge hose from vacuum harness "T". (Scheme 1) Attach Air Metering Fitting (6457) to manifold-mounted idle purge hose. Orifice size is.125" (3 mm). Connect Diagnostic Readout Box II (DRB-II) to vehicle.
3. Start engine and allow it to idle for at least one minute. Using DRB-II, access MINIMUM AIRFLOW IDLE SPEED. The AIS motor should fully close, and idle spark advance should be fixed. Ensure proper RPM is displayed on DRB-II.
4. Check idle RPM (minimum airflow rate) with tachometer. See V6 MINIMUM AIRFLOW RATE SPECIFICATIONS table. If minimum airflow rate is not to specification, replace throttle body. If minimum airflow rate is correct, turn engine off, and disconnect all test equipment.

V6 MINIMUM AIRFLOW RATE SPECIFICATIONS

Scheme 1

Minimum Airflow Rate (3.3L & 3.8L)

1. Ensure engine is at operating temperature. Connect tachometer to engine. Turn engine off. Turn off all lights and accessories. Disconnect PCV hose from intake manifold nipple. Attach Air Metering Fitting (6457) to intake manifold nipple. Orifice size is .125" (3 mm).
2. Disconnect 3/16" idle purge hose from throttle body, and plug nipple on throttle body. Connect Diagnostic Readout Box II (DRB-II) to vehicle. Start engine and allow it to idle for at least one minute.
3. Using DRB-II, access MINIMUM AIRFLOW IDLE SPEED. The AIS motor should fully close, and idle spark advance should be fixed. Ensure proper RPM is displayed on DRB-II.
4. Check minimum airflow rate. See V6 MINIMUM AIRFLOW RATE SPECIFICATIONS table. If minimum airflow rate is not to specification, replace throttle body. If minimum airflow rate is correct, turn engine off, and disconnect all test equipment.

THROTTLE POSITION SENSOR

Note. Throttle Position Sensor (TPS) is not adjustable. To check TPS calibration, see G - TESTS W/ CODES in the ENGINE PERFORMANCE Section.