Wife's '03 R50 has started to sound a little more put-put lately, and is now throwing an P0304 code every couple of days. P0304 is a cylinder 4 misfire. We also got the code for a random misfire (?)/low fuel once when the tank was, in fact, kind of low.

We replaced the plugs, coil pack (with a Screamin' Demon pack) and wires almost exactly a year ago on recommendation of a local MINI shop to take care of the P2097 code it was throwing. They then took care of resetting the fuel adaptations and car was running great.

It still gets good mileage, it just runs kind of rough at idle and throws the occasional code/CEL.

Where should I start- does fuel injector cleaner ever work? Do I try it more than once? Should I swap plugs, wires, injectors from cylinder #4 to another one? Should I put the original coil back in for a while? Should I try swapping injectors?

Any help is appreciated.

Val

 

Is it throwing the same code? I'd pull the number 4 plug and check it for fouling. If its good try a new injector. I'm not a fan of the cure in a bottle stuff.

 

Trash the Screamin Demon and replace it with an OEM coil.

 

Here is a picture of the #3 and #4 plugs I pulled out:



They do look different. I don't know enough about new plugs to determine on sight if they are fouled. You can see the "tip" on #4 is recessed a bit as compared to #3. I switched them to see if the code follows to the #3 cylinder. They don't look all that different but that little bit of recession might be what is causing the problem. I'll post if it throws the "P0303" code.

Val