Engine Controls - Trouble Shooting - No Codes: Other Jaguar S-type I

DETONATION (ENGINE KNOCK)

1. Blown head gasket.
2. Ignition timing too far advanced.
3. Incorrect valve timing.
4. Lean fuel mixture.
5. No coolant in radiator/engine (engine overheating).
6. Check knock sensors.
7. Stuck thermostat (engine overheating).
8. Wrong octane fuel.

DIFFICULT START (CRANKS OKAY)

1. Check air induction system for cracks and restriction.
2. Check engine coolant temperature sensor operation.
3. Check for cracks and poor connections at throttle body.
4. Check ignition coils primary connections and wiring harness.
5. Ensure EGR valve operation is correct.
6. Ensure wiring harness and connectors are not broken or loose.
7. Ensure engine has sufficient compression.
8. Ensure fuel injector operation is correct.
9. Ensure fuel system pressure and volume are correct.
10. Ensure fuel system residual pressure is correct.
11. Ensure ignition and valve timing are correct.
12. Check ignition coils.
13. Ensure ECM has correct voltage supply and is properly grounded.
14. Ensure vacuum hoses are not disconnected or damaged.

ENGINE BACKFIRES

1. Air leak into/from exhaust system.
2. Air leak past valve guides or valves.
3. Incorrect ignition timing.
4. Incorrect valve timing.
5. Intake manifold air leak.
6. Lean air/fuel mixture.
7. Valves sticking open.

ENGINE DOES NOT START (NO CRANK)

1. Battery not fully charged.
2. Loose or corroded battery terminals.
3. Starter motor inoperative.
4. Check engine ground straps.
5. Faulty ignition switch.
6. Faulty park/neutral position switch.

Feld Tech Tip

The following Field Tech Tip is available regarding the replacement of the shift lever assembly micro-switches to repair a "No Crank" condition. See FIELD TECH TIP .

ENGINE FAILS TO IDLE

1. Blocked or restricted exhaust system.
2. Blown head gasket.
3. Incorrect ignition timing.
4. Incorrect valve clearance.
5. Air intake system leak or blockage.
6. Check electronic throttle system.

ENGINE ROTATES, BUT FAILS TO START

1. Fuel system malfunction.
2. Ignition system malfunction.
3. Starter motor rotating too slowly.

ENGINE RUNS ROUGH (OFF IDLE)

1. Blocked or restricted exhaust system.
2. Blown head gasket.
3. Broken valve spring(s).
4. Burnt valve or valve seat.
5. Fuel system malfunction.
6. Ignition system malfunction.
7. Intake manifold air leak.
8. Sticking valves.

ENGINE STALLS

1. Check EGR system for correct operation.
2. Check engine coolant temperature sensor operation.
3. Check for cracks and poor connections at throttle body.
4. Check for distortion and cracks in fuel injector plastic connecting flanges.
5. Check for poor quality fuel, fuel with high alcohol content or contaminated fuel.
6. Check throttle position sensor operation.
7. Ensure air intake system is unrestricted.
8. Ensure fuel system pressure is correct.
9. Check crankcase ventilation system.
10. Check electronic throttle system.

LOSS OF POWER

1. Burnt or sticking valves.
2. Ensure engine compression is okay.
3. Fuel system malfunction.
4. Incorrect camshaft timing.
5. Incorrect valve clearance.
6. Ignition system malfunction.
7. Wrong octane fuel.

ROUGH OR UNSTABLE IDLE

1. Burnt valve or valve seat.
2. Fuel system malfunction.
3. Incorrect valve clearance.
4. Incorrect valve timing.
5. Incorrect ignition timing.
6. Ignition system malfunction.
7. Sticking valves.
8. Electronic throttle system fault.

Intermittent Simulation

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

1. Lightly vibrate component.
2. Wiggle or bend wiring harness.
3. Spray component with water mist.
4. Heat component.
5. Remove/apply vacuum source.

Monitor circuit/component voltage or resistance while simulating intermittent. If engine is running, monitor for DTCs. Use test results to identify a faulty component or circuit.