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| Home / Car Engines / Nissan Engines / Nissan A12 |
Nissan A12 Troubleshooting
| Engine doesn't start or starts hard |
Empty fuel tank - Add gasoline.
Incorrect fuel grade - Change fuel.
Air or water in fuel system - Remove water or air from fuel system.
Damaged spark plug wiring connection - Inspect spark plug wiring connection, change or repair.
Defective spark plug - Change spark plug as required.
Ignition failure - Test ignition and replace failed parts.
Clogged fuel filter - Replace fuel filter.
Clogged fuel lines - Service fuel lines.
Fuel pump is defective or dirty - Test fuel pump and replace if necessary.
Incorrect carburetor adjustment - Adjust carburetor idle mixture screw.
Engine has low compression - Check cylinder block and replace defective parts.
| Engine runs intermittently |
Ignition system is defective - Inspect ignition system and change failed components.
Air filter element is plugged - Replace or clean filter.
Spark plug is damaged - Replace spark plug.
Dirty or defective fuel pump - Service or change fuel pump.
Valve clearance is not correct - Adjust valve clearance according to specifications.
Improper ignition timing - Ignition timing needs to be set properly.
Low idle speed set incorrectly - Correct idle adjustment.
| Engine stops after starting |
Damaged spark plug - Change spark plug as required.
Carburetor is clogged or defective - Clean or install new carburetor.
Faulty ignition coil - Install a new ignition coil.
Worn or loose valve springs - Replace valve springs.
Valves are stuck - Clean the valves.
| Engine overheating |
Not enough engine oil - Check and refill engine oil.
Engine overload - Load reducing is recommended.
Carburetor is running lean - Make the correct settings.
Wrong ignition timing - Adjust ignition timing correctly.
Incorrect valve setting - Adjust valves correctly.
Dirty radiator core or faulty radiator cap - Clean radiator or install new cap.
Insufficient coolant - Top up coolant fluid and check system for leaks.
Defective thermostat - Change thermostat as required.
Water pump is defective - Install new water pump.
| Engine noise or knocking |
Low octane fuel - Change gasoline.
Engine overload - Load reducing required.
Engine oil level low - Fill the crankcase with engine oil.
Low idle speed set incorrectly - Adjust the low idle speed.
Fuel pump is dirty or defective - Check fuel pump and change if required.
Worn crankshaft or main bearings - Have bearings or crankshaft replaced.
Incorrect valve clearance - Adjust valve clearance.
Damaged cylinder bore or piston rings - Change faulty components.
| Engine power is too low |
Carburetor is improperly adjusted or dirty - Adjust carburetor properly or service it.
Air filter is blocked - Change or clean air filter.
Dirty or defective fuel pump - Service or change fuel pump.
Ignition system is defective - Check ignition and replace faulty components.
Damaged cylinder-head gasket - Replace the head gasket.
Valves are stuck or burned - Service or change valves.
Cylinder block components are damaged - Defective components need to be replaced.
Plugged oil filter - Change or service oil filter.
| Engine using too much gasoline |
Clogged air filter - Change or clean air filter.
Incorrect adjustment of carburetor main jet - Adjust it properly.
Loose or faulty spark plug - Tighten or replace spark plug.
Wrong ignition timing - Adjust ignition timing correctly.
Valves are stuck, burned, or worn - Change or service valves.
Rings, sleeve, or piston are damaged - Replace defective components.
Valve clearance is wrong - Adjust valve clearance.
Engine has bad compression - Check cylinder block and change wear parts.
| High oil consumption |
Gaskets or seals are excessively worn - Change worn parts according to specifications.
Valve guides and stems are worn - Install new valves.
Piston rings are stuck or broken - Piston rings need to be replaced.
Cylinder liner or piston is worn - Inspect piston and liner, fit new components as necessary.
| Engine backfires |
Carburetor is running lean - Adjust carburetor properly.
Dirty fuel lines - Fuel lines need to be cleaned.
Bad ignition timing - Adjust ignition timing correctly.
Improper valve setting - Valves needs to be set correctly.
Air filter is dirty - Service or replace air filter.
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