Engine Controls - Tests W/o Codes: Other Toyota Camry XV10

DIFFICULT TO START/NO START (WON'T CRANK OR CRANKS SLOWLY)

1. Check battery and cables, charging system and fusible links.
2. Check ignition switch.
3. Check starter relay.
4. Check clutch start switch (M/T) or neutral start switch (A/T).
5. Check starter and wiring connections.

DIFFICULT TO START/NO START (CRANKS OKAY)

1. Check for vacuum leaks (oil filler cap, oil dipstick, hose connections, PCV valve and hose).
2. Verify secondary ignition system performance.
3. Check cam position sensor (if equipped).
4. Ensure ignition timing is correct.
5. Check auxiliary air valve (if equipped).
6. Ensure fuel system (pump, lines, filter and pressure regulator) performs properly.
7. Verify proper compression and valve clearance.
8. Check circuit opening relay.
9. If engine starts with accelerator pedal depressed, check idle speed control valve (if equipped) and wiring connection.
10. Check fuel pump switch in airflow meter.
11. Check wiring connection to ECU.
12. Check power to ECU via fusible links, fuses and EFI main relay.
13. Check airflow meter, coolant temperature sensor and air temperature sensor.
14. Check injection signal circuit.

ENGINE STALLS OFTEN

1. Check for vacuum leaks (oil filler cap, oil dipstick, hose connections, PCV valve and hose).
2. Ensure fuel system (pump, lines, filter and pressure regulator) performs properly.
3. Check air filter.
4. Check idle speed and ensure ignition timing is correct.
5. Verify secondary ignition system performance.
6. Verify proper compression and valve clearance.
7. Check cold start injector and cold start injector time switch.
8. Check auxiliary air valve (if equipped) or idle speed control valve (if equipped).
9. Check circuit opening relay.
10. Check fuel injectors.
11. Check power to ECU via fusible links, fuses and EFI main relay.
12. Check airflow meter, coolant temperature sensor and air temperature sensor.
13. Check injection signal circuit.

ENGINE STALLS SOMETIMES

1. Check airflow meter and connectors.
2. Check EFI main relay, circuit opening relay and connectors. Check for slight change in engine idle when connector or relay are slightly tapped or wiggled.

ROUGH IDLE/MISSING

1. Check for vacuum leaks (oil filler cap, oil dipstick, hose connections, PCV valve and hose).
2. Check air filter.
3. Check idle speed and ensure ignition timing is correct.
4. Verify secondary ignition system performance.
5. Verify proper compression and valve clearance.
6. Check variable induction system (if equipped).
7. Check cold start injector and cold start injector time switch.
8. Ensure fuel system (pump, lines, filter and pressure regulator) performs properly.
9. Check fuel injectors.
10. Check power to ECU via fusible links, fuses and EFI main relay.
11. Check airflow meter, coolant temperature sensor and air temperature sensor.
12. Check injection signal circuit.
13. Check O2 sensor(s).

HIGH IDLE SPEED (NO DROP)

1. Check accelerator linkage.
2. Check power steering idle-up circuit (if equipped).
3. Check A/C idle-up circuit (if equipped).
4. Check idle speed control valve (if equipped) or auxiliary air valve (if equipped) and wiring.
5. Check variable induction system (if equipped).
6. Ensure ignition timing is correct.
7. Check throttle position sensor.
8. Check for high fuel pressure.
9. Check for leakage at cold start injector or fuel injectors.
10. Check power to ECU via fusible links, fuses and EFI main relay.
11. Check airflow meter, coolant temperature sensor and air temperature sensor.
12. Check injection signal circuit.

ENGINE BACKFIRES (LEAN FUEL MIXTURE)

1. Check for vacuum leaks (oil filler cap, oil dipstick, hose connections, PCV valve and hose).
2. Check idle speed and ensure ignition timing is correct.
3. Check cold start injector and cold start injector time switch.
4. Ensure fuel system (pump, lines, filter and pressure regulator) performs properly.
5. Check for clogged fuel injectors.
6. Check power to ECU via fusible links, fuses and EFI main relay.
7. Check airflow meter, coolant temperature sensor, throttle position sensor and air temperature sensor.
8. Check injection signal circuit.
9. Check O2 sensor(s).

MUFFLER EXPLOSION (RICH FUEL MIXTURE)

1. Check idle speed and ensure ignition timing is correct.
2. Check cold start injector and cold start injector time switch.
3. Ensure fuel system (pump, lines, filter and pressure regulator) performs properly.
4. Check for fuel injector leakage.
5. Verify secondary ignition system performance.
6. Verify proper compression and valve clearance.
7. Check throttle position sensor, injection signal circuit and O2 sensor(s).
8. Check for exhaust system leaks.

ENGINE HESITATES/POOR ACCELERATION

1. Check for clutch slipping or brakes dragging.
2. Check for vacuum leaks (oil filler cap, oil dipstick, hose connections, PCV valve and hose).
3. Check air filter.
4. Check for leakage or clogging between air filter and turbocharger inlet and between turbocharger outlet and cylinder head (if equipped).
5. Verify secondary ignition system performance and timing.
6. Verify proper compression and valve clearance.
7. Ensure fuel system (pump, lines, filter and pressure regulator) performs properly.
8. Check for clogged fuel injectors.
9. Check variable induction system (if equipped).
10. Check power to ECU via fusible links, fuses and EFI main relay.
11. Check airflow meter, coolant temperature sensor, air temperature sensor and throttle position sensor.
12. Check injection signal circuit.

Intermittent Simulation

To reproduce the conditions creating an intermittent fault, use the following methods

1. Lightly vibrate component. See VIBRATION METHOD.
2. Heat component. See HEAT METHOD.
3. Wiggle or bend wiring harness. See VIBRATION METHOD.
4. Spray component with light water mist or radiator with water. See HUMIDTY METHOD.
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.

HEAT METHOD

Apply heat to a suspected component with a hair dryer or similar device and monitor suspected circuit or component with a DVOM.

HUMIDITY METHOD

If humidity or moisture are suspected of causing an intermittent failure, spray water on the radiator to increase humidity in the engine compartment. Check if a malfunction occurs by monitoring the suspected circuit or component with a DVOM.

If a vehicle is subject to water leakage, the admitted water may contaminate the ECU. When testing a vehicle where water leakage has occurred, carefully inspect the ECU terminals for corrosion. Repair or replace the ECU connectors as required.

ELECTRICAL LOAD METHOD

To check if an intermittent occurs under electrical load, turn on all electrical loads (heater blower, headlights, rear window defogger, wipers, etc.). Check if the malfunction occurs by monitoring the suspected circuit or component with a DVOM.