Hello all,
I need advice from someone out there. In the last year my check engine light has gone on and off. It has always been P0300 - Random Engine Misfire and no other codes show up. I have replaced the Fuel Pump, Belt Tensioner, Spark Plugs, Plug Wires, and the Coil Pack. The idle is rough and the light usually goes on when I'm on the highway and sometimes when I start him it usually is not quick to turn over. Im running out of ideas and patience, does anyone else know what it might be??

 

What is the mileage on the car and was any major engine service performed?

For the Gen1 Minis, some of the causes of P0300 engine misfire includes:

- clogged fuel injectors
- fuel pump
- ignition coil
-engine compression (carbon buildup or bad rings?)

Sounds like you have covered the pump & coil.

Might try fuel injector cleaner additive (or remove and have the injectors tested), and also try a compression check to see if all cylinders are even.

Hope this helps!

Drive Hard. Drive Safe. Keep Grinning.