Question

2000 Ford Ranger 4.0L with codes P0300 and P0303 misfire, this started out as rough idle at startup only. Does that make it any easier to decode?

Answer 1

Check the spark plugs first, then the coils or distributor

but there are many other causes to check like

- Faulty spark plug 3
- Faulty ignition coil 3
- Ignition coil 3 harness is open or shorted
- Ignition coil 3 poor electrical connection
- Clogged or faulty fuel injector 3
- Injector 3 harness is open or shorted
- Injector 3 poor electrical connection
- Improper spark plug 3
- Insufficient cylinder 3 compression
- Incorrect fuel pressure
- Intake air leak