Cylinder misfire p0300

START THE ENGINE AND LIFT THE IGNITION WIRE LISTEN FOR SPARKS.IF ONE OR MORE CYLINDERS DON'T CHANGE THE WAY IS RUNNING ,YOU GOT THE BAD CYLINDER. LOOK FOR BURN MARKS ON THE WIRE(BLUE/WHITE SPOT)IF SO REPLACE THE WIRE.SOME TIMES VALVE COVER LEAKING IN THE TUBE. REPLACE VALVE COVER GASKET,BLOW THE OIL OUT BEFORE REMOVE THE SPARK PLUGS.REMOVE THE SPARK PLUGS AND INSPECT THE ELECTRODE.GOOD ELECTRODE WILL BE WITH SHARP EDGE ,IF ROUND OR LIKE CONE REPLACE WITH DENSO OR NGK ORIGINAL EQUIPMENT . REMOVE THE DISTRIBUTOR CAP AND LOOK FOR OIL IN THE CAP. IF OIL INSIDE REPLACE DISTRIBUTOR. IF NO OIL INSPECT THE CAP AND ROTOR FOR THICK WHITE DEPOSIT OR ROTOR FOR BLACK BURN MARKS. REPLACE CAP AND ROTOR.IF EL.SYSTEM IS OK SPRAY CARB CLEANER ON INTAKE MANIFOLD AND LISTEN FOR RPM CHANGE.IF CHANGE THE RPM REPLACE MANIFOLD GASKET.

CHECK THE PLUG AND CABLE FOR THAT CYLINDER OR THE
CYLINDER ITSELF.

Have to get your codes & diagnose the misfires,
& a dozen things that can cause them

All you need to study is on the internet

Not about working a car anymore

It's about knowledge & studying before
you go out to the car

That is 80% of vehicle diagnostics (knowledge,
proper & expensive test equipment & the ability to use it)

Usually start with Spark Plugs if they are in the motor 3 years or more,if not that long, move on to ignition coils or modules for
a possible problem

Have to isolate the misfire to a cylinder or two

Have to make sure their are no Vacuum Leaks anywhere
& you have control over the fuel delivery

Hard to do all that with out professional tools