Okay, I think mine's getting worse. It seems to do it more consistently when I go to start it the morning after a long / spirited drive. For example, we just went camping over the weekend & there were tons of fun, twisty roads leading to the site. I went to start it the morning after we packed up & it threw the cyl #2 misfire code & took three re-starts to get the motor idling properly. Gonna do a compression test today & check out the plugs. So far it seems like fuel injector terminal corrosion / o-rings are the most common culprit, yeah?

 

Please let me know what you find as I am having very similar issues now too. I had a starting issue the other morning while heading to the airport, the check engine light came on and stayed on for a long 2.5 hour drive. After the drive and sitting for 5 days I returned and the light was off and the car started right up. I had autozone pull the code from the memory and it came up as a P0340 code (camshaft sensor error). I am being told that this is related to the problem but I am not sure and would like to see what you and others have in mind.

 

Aright, I got a little time to work on this today. I did a compression test & came up with the numbers:
1-180
2-180
3-178
4-176

So then, compression is fine, which is great because that means the issue probably isn't valves or injector o-rings.

What I did notice when I pulled the plugs, however, was that the electrodes / ground straps look pretty similar across all cylinders, but the threaded section of #2 looked much different than the others. Also, #2 was much more resistant to unthreading than the others. See below:





So then, I'm guessing that the issue is with fuel delivery. Next weekend I'll try pulling the intercooler & cleaning / reseating the injector's electrical terminals.

 

After hours and hours of forum searching talking to others, and looking at possible issues I finally found out what it is and I am 100% the same issue is what you are experiencing too. Do you get a check engine light or code when this happens? Either way look into the CAM sensor located between the engine and the passenger engine mount.

 

I think its a computer (DME) problem.....100%. If it was a spark plug, iginition, fuel injector, compression....or some other kind of mechanical problem.....it wouldn't happen one time and then go away. Unless your car is doing it every single time you try to start it. I think most people (like me) have the starting "bobble and die" issues a couple of times and then it goes away for days/weeks/months....then dies it again out of the blue.

If it was some kind of mechanical problem, it wouldn't come and go like that.

 

I am telling you its the CAM sensor. My car was doing the exact thing! See this link I posted up and finally got it fixed thanks to pelican

https://www.northamericanmotoring.co...code-help.html

 

Mine hasn't done it since I got a new battery. Nothing wrong with the old one, but it was an incorrect size. Put the new one in and it has been good for about 12 months. Can't remember for sure, but I don't think I have had anything else done to the engine in that time.

James

 

This is awesome, I will check out my cam sensor for sure! Did yours turn out to be the sensor itself or the connection to the sensor (corrosion, etc.)?

 

I checked all the connections to the sensor and they seemed ok, but as a test I pulled the connection to the sensor and started the car up EXACT same issue with sputtering and lights that came on multiple mornings before. Reconnected the sensor nice and tight, reset the ECU, and cleared all codes. NOTHING runs like a top! EVEN getting better gas mileage now by like 3MPG

 

Alright, well I just tried re-seating the cam sensor & it did nothing. Though I didn't try resetting the ECU, the plug to the cam sensor looked brand new, no corrosion whatsoever. Also, if the code you were getting was for the cam sensor, that makes sense. I'm getting a P0302 for a cylinder 2 misfire which is why I suspect an injector issue...

 

Oh ok gotcha. It was worth a try, I was getting P0340 code. Cam Position Sensor. Sorry it didnt help. Keep us posted

 

Okay, I think I have a pretty good idea as to what's causing it. Based on these three symptoms:

-Car consistently throws misfire code for cylinder two
-Once car does fire up, there is a strong fuel smell
-If you hold idle around 3k RPM for a few seconds, it will right itself and not return until after the car has sat for a while

What do all of these point to?? Leaky fuel injector in cylinder 2. I bet that gas is just drip-drip-dripping into cylinder two while the car sits there, creating a puddle in the combustion chamber & horribly throwing off the A/F ratio for that cylinder when I fire it up. Once I hold it to 3k RPM, it sucks all that extra fuel through the exhaust ports, correcting the A/F ratio and emitting a temporary strong fuel smell.

All adds up to me, thoughts? This weekend I'll be pulling the injectors & leak testing them by pumping pressurized air into the inlet & putting the nozzle under water. I bet I see bubbles from injector #2....

If this is the case, anyone know where I can source a new OEM injector? I really have no desire to upgrade to a higher flow set of injectors & can't find a ton of info on the OEM R53 injectors....

 

Take the number 2 injector and swap it with another on the car. If the code moves, then you know it's the injector. If it stays at 2 then you know it is something else. You might also get a new set of O-rings for them since you have them out and they are dirt cheap. If you need another one, just check on the classifieds as I'm sure a lot people have them laying around.

 

Small update, I tried swapping plugs between cylinders 2 & 3 yesterday. Today, when I started the car I got an SES light, scanned it, and it has turned into a P0300, Random / Multiple Cylinder Misfire Detected. So then, maybe it's ignition related after all? Today I'll dig in deeper, investigating the coil, harness, wires, injectors, o-rings, everything. Will report back soon!

 

Hmm waiting patiently

 

Alright, I tore into it this weekend & learned a lot but gained little. I pulled the fuel rial / injectors & pressure-tested them (20psi into the inlet via bike pump & held the nozzle under water to look for bubbles.) No bubbles. So, I cleaned out all of the injectors while they were out w/ brake cleaner & pulsing them open/closed w/ a 9v battery & back flushed them in case any debris was caught in them. My local APS also happened to have the injector o-rings in stock so I went ahead & replaced those as well (originals actually still looked pretty good). Also, all of the injector's electrical terminals looked brand new. When I put it all back together, I swapped injectors #1&2 just in case.

So then, I went to start it up and VROOM! No sputtering or misfiring at all! It continued like this for the rest of the weekend, whether it sat over night or just a few hours. I figured "well, even though it wasn't a leaking injector, something must've gotten tweaked that fixed it! Hooray!

Until this morning, when I fired it up & it misfired on cylinder 2 again.....

My last remaining test is the coil. Luckily, my girlfriend also has an R53, so I will swap the coils this evening & see if the problem moves to her car! haha

 

Wow, I was excited until the end of that story. Hope it works out with the coil..

 

You might want to put some anti-seize on the plugs. If you don't torque them to the right specs, our cars are know to blow plugs , I'm sure you know this anyways. The anti-seize just makes it better when taking them out (acts as a release agent) and helps eliminate any corrosion from moisture and chemicals on the threads.

With all that said....all my 3 Minis sputter in the morning during cold startup. :-/ And I have absolutely NO idea what it is....they still run pretty well though.

Manny

 

Are we all just going to have to live with it??

 

Apparently we do have to just live with it. Silence is having a different problem from what most of us get. I never get any codes from this.

After sputtering and dying on the first try, then running great on the second try, almost every day for a week, then starting fine for the next week, it did it again yesterday.

I think you Steffen suggested bad summer gas might be the problem, and since our cars run fine after starting, it could be the problem. Use a gas additive maybe? I just don't worry about it since it has always started on the second try. Winter is also coming, and it never does it then

 

Check for corrosion on the coil pack connections to the spark plug wires. If you have corrosion on the connectors, sand papering it off will not always fix the problem. There's a good chance there's corrosion on the plug wire side also which is harder to clean. After getting rid of the corrosion you can use something like battery terminal spray or DeOxit on the connectors to help prevent it coming back.

 

I also get codes as well almost always the P0340 code and I just picked up a CAM Position sensor to put in next weekend that I hope will fix this. The gas issue is only supposed to happen once or twice as we switch from winter/fall to summer gas. I am getting this issue more than once or twice.

 

Alright, well I'm almost positive mine's a head gasket now :-/ This morning I got up, started the car (with the coil pack from the other R53) and it misfired on cylinder 2. I popped the hood & the coolant expansion tank had MASSIVELY overflowed on my previous drive. I pulled the cap & there's oil in the coolant So then, ordering all of the necessary parts to do my head gasket next weekend.....

 

No water in the oil though?

Definitely could have a bad head gasket, but oil in the water isn't going to make it misfire only on cylinder 2.

Saw your compression was good, did you do a leak down test too?

I guess either way you've tried just about everything electrical and the next step is pulling the head. Good luck

 

Keep us posted..