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| Home / Car Engines / Nissan Engines / Nissan HR12DE |
Nissan HR12DE Troubleshooting
| Engine is not starting or hard starting |
No fuel in fuel tank - Add fuel.
Wrong grade of gasoline - Change gasoline.
Clogged fuel system - Remove clogging.
Spark plug wiring connection is defective - Inspect the spark plug wire connection, replace or repair.
Spark plug is defective - Change spark plug as required.
Ignition system is defective - Inspect ignition system and change failed components.
Fuel filter is clogged - Install new filter.
Fuel lines clogging - Clean fuel system lines.
Clogged or damaged fuel pump - Clean or change fuel pump.
Fuel injectors are clogged or faulty - Clean or change fuel injectors.
Weak cylinder compression - Inspect cylinder block and change worn parts.
| Unstable engine running |
Ignition system malfunction - Check ignition and replace faulty components.
Plugged air filter - Change or clean air filter.
Faulty spark plug - Change spark plug as required.
Fuel pump is defective or dirty - Test fuel pump and replace if necessary.
Valve clearance is improper - Adjust valve clearance.
Ignition timing is improper - Ignition timing needs to be adjusted correctly.
Low idle speed setting is not correct - Correct the settings.
| Engine starts but then stops |
Damaged spark plug - Change spark plug.
Dirty or defective fuel injectors - Inspect fuel injectors and change as required.
Ignition coil is faulty - Ignition coil should be replaced.
Valve springs are bad or broken - Valve springs need to be changed.
Valves sticking - Valves need to be cleaned.
| Engine overheated |
Engine oil insufficient - Add oil to the engine crankcase.
Engine overloaded - Reduce load.
Fuel injectors are clogged - Check fuel injectors and clean if necessary.
Ignition timing is incorrect - Set the ignition timing properly.
Wrong valve setting - Adjust valves as required.
Dirty radiator core or defective radiator cap - Clean radiator or replace cap.
Low coolant level - Top up coolant fluid and check system for leaks.
Faulty thermostat - Install new thermostat.
Water pump failure - Replace water pump.
| Engine noises or knocks |
Stale gasoline - Use proper fuel.
Engine is overloaded - Reduce load.
Engine oil level low - Checking oil level and add if necessary.
Incorrectly adjusted low idle speed - Adjust as required.
Fuel pump is clogged or faulty - Check fuel pump and change if required.
Crankshaft or main bearings failure - Install new parts as as required.
Excessive valve clearance - Check and adjust.
Worn cylinder bore or piston rings - Replace defective components.
| Engine power is too low |
Fuel injectors are faulty or clogged - Test fuel injectors and replace if necessary.
Clogged air filter - Service or replace air filter.
Fuel pump is faulty or clogged - Test fuel pump and replace if necessary.
Defective ignition - Inspect ignition system and change failed components.
Cylinder head gasket is worn - Install new head gasket.
Valves are stuck or burned - Change or service valves.
Damaged cylinder block components - Defective parts need to be replaced.
Plugged oil filter - Clean or change oil filter.
| Engine uses too much fuel |
Air filter element is clogged - Change or clean air filter.
Fuel injectors are defective or dirty - Test fuel injectors and change if necessary.
Spark plug is defective or loose - Re-tighten or replace spark plug.
Wrong ignition timing - Adjust ignition timing as required.
Valves are stuck, burned, or worn - Clean or replace valves.
Worn sleeve, rings, or piston - Change defective parts.
Valve clearance is wrong - Adjust valve clearance.
Bad compression - Check and change damaged parts.
| High oil consumption |
Worn gaskets or seals - Replace to repair leaks.
Valve stems and guides are worn - Change the valves.
Worn or stuck piston rings - Piston rings need to be replaced.
Scored piston or cylinder liner - Check piston and liner, replace as required.
| Engine backfires |
Clogged fuel injectors - Test fuel injectors and clean if necessary.
Dirt in the fuel lines - Clean fuel lines.
Ignition timing is incorrect - Set the ignition timing properly.
Wrong valve setting - Set the valves properly.
Plugged air filter - Replace or service air filter.
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