Hello Everyone,


I recently purchased a six speed 2005 R53 and almost immediately started having an issue. The car runs fine until I come to a stop (stop light, generally speaking) and then it begins to misfire. This usually doesn't happen right away, but 15-20 seconds after I come to a stop. It happens 90% of the time if the car is left with the shift lever out of gear (my foot gets tired stepping on the clutch sometimes). If I leave it in gear and slipped the clutch and give it a little gas, inching it forward, every 10-15 seconds, it doesn't misfire. I have replaced the coil with an OEM coil, but I have not replaced plugs or wires, which I assume is the next step. I haven't read anything in any of the forums similar to this situation so I decided to ask you guys if you have any other ideas other than plugs and wires.


From other posts I've read that the following are also potential issues:
DSC module
Injector/s
MAP sensor (spray with carb cleaner)
Valve Guides


I've also noted that JCW plugs may help along with using chevron techron.


Any help would be appreciated!

 

Do you actually have misfires with the check engine light on or flashing? Or the idle is kinda erratic?

Minis are known to act funny at stop lights (with stock ecu that is), rpm going low then climbing back up.

 

Get a compression test....
Bet you have low compression...likely from a burnt valve from low octane fuel...car REQUIRES 90-91 if unmodified... Maybe a prior owner used midgrade or less...
The mechanics is at idle, the air is leaking out...hense a misfire...
At higher rpms, the air/fuel has less time to leak out and runs ok...
Typically the misfires will get worse and at higher rpms as it progresses...
Just my guess...

 

Thank you guys for the response.

Yes, it is a misfire with the check engine light flashing.

How much is a compression test and where do I get it done? If it is compression, what will I need to do and how much will that cost?

I have a baby on the way, so if I need to sell the car, I might as well trade it in now...

 

Not sure the $$ for a compression test....but cheap and easy.
A spark plug is unscrewed (you can examine it for wear and condition), a adaptor with a guage attstched is screwed into the sparkplug hole...the car is the cranked...(for a dry check...can be done with a spoonful of oil as a "wet" test...a skilfull mechanic can use the difference between these two tests and tell you if a piston ring is bad or a valve).....sometimes compressed air can be added and a "leakdown"test done...gives a mechanic more info...and can listen for where the sound is comming from.....
I hope it is just bad plug....but I think somebody might have dumped a car with a devolping issue...my guess... Good luck to you. With info you can decide to spend more $$ or run!!.

 

You can go to your local autozone/checkers and rent a compression test kit for basically nothing. Like stated just unscrew one spark plug screw on the gauge and crank the engine. Repeat for each cylinder. They should all be around the same psi. Make sure to start the plugs and guage adaptor with your fingers so you don't cross thread!