Ignition System Problems:
* Bad spark plugs: Worn, fouled, or improperly gapped plugs can prevent proper combustion.
* Worn or damaged distributor cap and rotor: These components distribute the high voltage to the spark plugs. Cracks or corrosion can lead to misfires or no spark.
* Ignition coil failure: The coil provides the high voltage needed for sparking. A weak or faulty coil will result in weak sparks or no spark.
* Ignition module failure: The module controls the firing sequence of the coil. Failure here can lead to misfires or complete engine shutdown.
* Worn or faulty ignition wires: Damaged or corroded wires can short-circuit or prevent voltage from reaching the plugs.
* Bad crankshaft position sensor (CKP sensor): This sensor tells the computer the position of the crankshaft, which is crucial for proper ignition timing. A faulty sensor can cause misfires or no start.
Fuel System Problems:
* Low fuel pressure: Insufficient fuel pressure prevents adequate fuel delivery to the cylinders.
* Clogged fuel filter: A clogged filter restricts fuel flow.
* Fuel pump failure: The pump may be weak or failing altogether.
* Fuel injectors malfunctioning: Clogged or leaking injectors can cause misfires or uneven running.
Other Potential Issues:
* Vacuum leaks: Leaks in the intake manifold or vacuum lines can disrupt the air-fuel mixture.
* Compression issues: Low compression in one or more cylinders prevents proper combustion. This could be due to worn rings, valves, or head gasket problems.
* Timing issues: Incorrect timing can lead to misfires or poor performance.
* Computer problems (ECM/PCM): A faulty engine control module can cause a wide variety of problems, including misfires.
To help me diagnose your specific issue, please tell me:
* What exactly is happening? Is the engine running rough, misfiring, backfiring, or completely refusing to start? Be as descriptive as possible.
* When did this problem start? Did it happen suddenly or gradually?
* What recent work has been done on the engine? Any repairs or modifications?
* What are the symptoms? Any unusual noises, smoke, or smells?
With more details, I can give you a more specific and helpful answer. Remember, diagnosing engine problems can be complex, and it's always a good idea to consult a qualified mechanic if you are unsure about what you are doing.
