Possible Causes
- Defective spark plugs, ignition cables, distributor cap/rotor, ignition coil or flywheel/pulse wheel
- Blocked/leaking injector
- Uneven compression
- Leakage between cooling system and cylinder
- Moisture, flashover in ignition system secondary side
- Intermittent open circuit , intermittent short-circuit to ground
- Intermittent short circuit to voltage supply
- Contact resistance or loose connection in ignition system low-tension side, in injector circuit or fuel pump circuit
- Engine oil level too high
- Air leakage
- Fuel pressure and residual pressure incorrect