Hi everyone,

I am a new mini owner, and I have kind of fallen in love with this car.

However, I keep having an issue with misfiring on cylinder 1 at idle. So far the spark plugs have been changed, the fuel injector has been changed out, we swapped the coils on two cylinders and the misfire persisted on cylinder 1.

I'm really confused, and I don't know what else I should be looking at to try to diagnose this problem.

Any help would be extremely appreciated.

Thanks!!

 

How many miles are on the car? I think if you have to much carbon build up it could cause a miss fire. I would make sure you also have the right spark plugs. I changed my plugs once and I took me 2 weeks until I realized I had the wrong sparkplugs. If you have done any kind of maintenance recently go back and check everything.

 

Thanks for your reply!

There are 99,000 miles on the car.

I will check out the carbon build up.

And the plugs are definitely the right ones. They were originally changed because the wrong ones were in the car.

 

The high pressure fuel pump can also cause misfires, though in my case the codes indicated multiple cylinders misfiring. The intake valves were pretty dirty, but even after walnut shell cleaning them the problem remained.

Error codes due to faulty HPFP on my 2009 Clubman S, 45,000 miles.
P0304 Cylinder 4 Misfire Detected
P0302 Cylinder 2 Misfire Detected
P2781 Misfire Mult Cyl Max
P2779 Misfire Cyl 4 Max
P277D Misfire Cyl 2 Max
P2783 Misfire Mult Cyl Error
P277B Misfire Cyl 4 Error
P277F Misfire Cyl 2 Error
P2773 Misfire Cyl 1 Error

 

The CEL is not coming on at all...

And I just had the fuel pump replaced. :(

 

Have the compression checked. Also, do a leak down test.

 

I had a coil failure in #2 in late summer, and it wouldn't produce a code for weeks... the engine would struggle and often die at idle, and NOT respond well to throttle input, so it was extremely frustrating. My shop tried boosting the idle but wouldn't do anything else until the code finally appeared. After fix, I still had slow throttle response. After some head-scratching, the shop (independent) deduced an air mass meter failure. Didn't produce a code, but that's where his experience led him. Took a week or so before performance leveled out again. It seems "normal" for the new meter and your engine to sort out the data and agree on idle conditions; one factor may be giving it plenty of varying rev speeds. For me, it didn't settle until I had driven many miles, AND spent one 10-minute period at idle in a parking lot. After that, fine. Good Luck!