Q: Bad misfiring issue - 2004 Nissan 350Z

Engine misfires can be caused by a list of problems, but there are a few suspects that occur more than others. Generally, misfires are caused by either a spark or fuel issue or in cases, a combination of both. Spark related problems generally will result from things like ignition coils, crankshaft position sensor, spark plugs, spark plug wires or ignition modules not working properly.

In your case, the low cylinder compression suggests that you may have excessively worn piston rings in cylinders #2 & 5, which can allow the oil to pass by the piston up into the combustion chamber causing the oil to be burnt along with the fuel. This will cause the motor to lose oil quickly and the spark plugs to foul out often. The result of a misfire or an explosion in that cylinder that is much less powerful than the other cylinders creates a loss of power that resonates throughout the motor additionally causing other problems with ignition and fuel timing.

If you’d like to get this fixed, I would recommend having an expert from YourMechanic come to your location to diagnose your misfiring problem and make the necessary repairs to your vehicle.