Engine Controls - Tests W/o Codes Acura Integra II

INTRODUCTION

Before diagnosing symptoms or intermittent faults, perform steps in BASIC TESTING and TESTS W/CODES articles in the ENGINE PERFORMANCE Section. Use this article to diagnose driveability problems existing when a hard fault code is not present.

Note. Some driveability problems may have been corrected by manufacturer with a revised computer calibration chip or computer control unit. Check with manufacturer for latest chip or computer application.

Symptom checks can direct technician to malfunctioning component(s) for further diagnosis. A symptom should lead to a specific component, system test or adjustment.

Use intermittent test procedures to locate driveability problems which do not occur when vehicle is being tested. These test procedures should also be used if a soft (intermittent) trouble code was present but no problem was found during self-diagnostic testing.

Note. For specific testing procedures, see appropriate SYSTEM/COMPONENT TESTS article in the ENGINE PERFORMANCE Section. For specifications, see ADJUSTMENTS or SPECIFICATIONS articles in the ENGINE PERFORMANCE Section.

SYMPTOM DIAGNOSIS

Symptom checks cannot be used properly unless problem occurs while vehicle is being tested. To reduce diagnostic time, ensure steps in BASIC TESTING and TESTS W/CODES articles in the ENGINE PERFORMANCE Section were performed before diagnosing a symptom. Symptoms available for diagnosis include:

1. Engine will not start.
2. Difficult cold start.
3. Fast idle out of specification.
4. Rough idle when warm.
5. Idle RPM high when warm.
6. Idle RPM low when warm.
7. Stalling during warm up.
8. Stalling after warm up.
9. Misfire or rough operation.
10. Emission test failure.
11. Lack of power. Recommended system and component checks may not apply to all vehicles.

ENGINE WILL NOT START

Ensure steps for spark and fuel testing in BASIC TESTING article in the ENGINE PERFORMANCE Section have been performed. Test ECU power and ground circuits. On Legend, also check coolant temperature sensor.

DIFFICULT COLD START

Check coolant temperature, MAP, TDC (Integra) and CRANK/CYL sensors. Check ECU, injectors and idle control system components.

FAST IDLE OUT OF SPECIFICATION

Check idle control system components and fuel supply system. Check coolant temperature and throttle position sensors.

ROUGH IDLE WHEN WARM

Check EACV operation, injectors, EGR system and other emission components. Check MAP, O2, crank angle, throttle position and intake air temperature sensors.

IDLE RPM HIGH WHEN WARM

Check EACV and idle control system components. Check MAP sensor, air intake system and emission systems.

IDLE RPM LOW WHEN WARM

Check EACV, air intake system, MAP sensor, injectors, EGR system and idle control system components.

STALLING DURING WARM UP

Check EACV, air intake system, idle control system components, fuel supply system and EGR system. Check MAP, crank angle, coolant temperature and throttle position sensors.

STALLING AFTER WARM UP

Check EGR system, EACV, air intake system and fuel supply system. Check MAP, throttle position, crank angle and vehicle speed sensors.

MISFIRE OR ROUGH OPERATION

Check each injector at idle. Check fuel supply, EACV, ignition output signal and EGR system. Check MAP, O2, crank angle and throttle position sensors.

EMISSION TEST FAILURE

Check injectors and all emission control components. Check MAP, O2, crank angle and coolant temperature sensors.

LACK OF POWER

Check for binding brakes or plugged exhaust. Check fuel supply system, emission control components, injectors, air intake system and EGR system. Check MAP, throttle position, coolant temperature and vehicle speed sensors.

INTERMITTENT PROBLEM DIAGNOSIS

Intermittent fault testing requires duplicating circuit or component failure to identify problem. These procedures may lead to computer setting a fault code (on some systems) which may help in diagnosis.

If problem vehicle does not produce fault codes, monitor voltage or resistance values using a DVOM while attempting to reproduce conditions causing intermittent fault. A status change on DVOM indicates a fault has been located.

Use a DVOM to pinpoint faults. When monitoring voltage, ensure ignition switch is in ON position or engine is running. Ensure ignition switch is in OFF position or negative battery cable is disconnected when monitoring circuit resistance. Status changes on DVOM during test procedures indicate area of fault.

TEST PROCEDURES

Intermittent Simulation To reproduce conditions creating an intermittent fault, use following methods:

1. Lightly vibrate component.
2. Heat component.
3. Wiggle or bend wiring harness.
4. Spray component with water using spray bottle.
5. Remove/apply vacuum source. Monitor circuit/component voltage or resistance while simulating intermittent. If engine is running, monitor for self-diagnostic codes. Use test results to identify a faulty component or circuit.

See also:
• BASIC TESTING