What causes a cylinder misfire?
What you need to know:
- During this phase of the combustion cycle, the closed air intake valves and piston rings are critical for preventing leakage of compression.
- Should a compression test reveal that cylinder 6 compression values are out of range compared to the nominal threshold or the other cylinders, then an investigation of engine intake valves and piston rings should be done.
Hello Paul, my 2003 Mitsubishi Pajero V6 3.5L petrol has a misfire from cylinder 6 confirmed by a computer diagnosis. My mechanic has checked the spark plugs, ignition coil, fuel injector and they all seem to be fine.
We are perplexed. We have also noticed some blue smoke. What can be the cause of this misfire? Charles.
Charles, if the components you have mentioned are okay you will need to rule out a circuit fault between the fuel injector and the engine computer. Also check ignition coil circuit.
Circuit failure can be caused by anything ranging from a damaged socket, harness or engine computer. If circuit failure is ruled out then ask the mechanic to carry out an engine compression test. This could be justified by the blue smoke which suggests burning engine oil.
Engine compression is essential for good engine performance and is built up during the compression stroke. This is when the fuel air mixture is sealed in the engine and compressed for charging.
During this phase of the combustion cycle, the closed air intake valves and piston rings are critical for preventing leakage of compression.
Should a compression test reveal that cylinder 6 compression values are out of range compared to the nominal threshold or the other cylinders, then an investigation of engine intake valves and piston rings should be done.
