A misfire is an ignition failure in one or more engine cylinders. It occurs when combustion does not occur properly due to problems in the air-fuel mixture, ignition spark or cylinder compression. An engine with a misfire experiences unstable slowing, loss of power, excessive vibrations and, in some cases, exhaust smoke or irregular blasts.
Main causes of a misfire:
Failure in the ignition system
👉▪ Worn, dirty or poorly calibrated spark plugs.
👉▪ Defective ignition coils or cracked in insulation.
👉▪ Damaged or high strength spark plug wires.
Problems in fuel supply
👉▪ Obstructed injectors or with defective spray pattern.
👉▪ Fuel pump with insufficient pressure.
👉▪ Faulty fuel pressure regulator.
✍️ Mishaps in the air-fuel mixture
👉▪ MAF or MAP sensor with incorrect readings.
👉▪ Air intake not measured by a leak in the admission multiple.
👉▪ Oxygen sensor in bad condition, generating rich or poor mixture.
Failure in cylinder compression
👉▪ Burnt or poorly installed intake or exhaust valves.
👉▪ Loss of compression due to worn piston rings.
👉▪ Damaged back gasket, causing compression leaks.
OBD-II codes related to misfire and their meaning
OBD-II system records ignition faults with codes P0300 to P0312.
Generic codes of misfire:
👉▪ P0300 - Random Misfire on Multiple Cylinders
👉▪ P0301 - Misfire on Cylinder 1
👉▪ P0302 - Misfire on Cylinder 2
👉▪ P0303 - Misfire on cylinder 3
👉▪ P0304 - Misfire on cylinder 4
👉▪ P0305 - Misfire on Cylinder 5
👉▪ P0306 - Misfire on cylinder 6
👉▪ P0307 - Misfire on Cylinder 7
👉▪ P0308 - Misfire on cylinder 8
Specific misfire codes under certain conditions:
👉▪ P0313 - Misfire detected with low fuel level
👉▪ P0314 - Misfire in a single cylinder, not specifying which
👉▪ P0316 - Misfire detected during engine start
Diagnosis and solution of a misfire
✍️1. Scan the vehicle with an OBD-II to identify the specific code.
✍️2. Check the
No comments:
Post a Comment