So I recently (2 months ago) purchased a 2011 R56 with a factory JCW tune and exhaust. Everything was fine until about 2-3 weeks ago when it got cold (was in the 20s for a week or so). The car was very slow to crank, which I figured out was the battery (the original one was still in it sigh), so I replaced the battery with a new dry cell one and it cranks and starts in 1-2 seconds flat now. Massive improvement there, go figure. What it didn't fix, however, was the sputtering I experienced upon cold starting it. If I start it and don't give it very light amounts of gas, it'll die. If I give it too much, it'll die. At first this only happened when it was really cold. Then it began to happen each and every time I cold started it, even if it was warm enough for the air conditioner to kick on. Today I started it and the auto-A/C started blowing hard and the engine just died. I started it again and it ran after some mild gas, as usual. Weird. I have also experienced sputtering at about 60-70 while flooring it a time or two. I haven't been able to replicate it at low speeds, and it may only occur at speed when the A/C is on, but I haven't had time to test that specific theory yet. Lastly.. I've noticed the pop and burble of the exhaust, very prominent once, has all but vanished. I drive with sport mode on quite often and I never hear it anymore (though sometimes on the interstate I think I hear it).

When it first began to sputter on startup, it threw this code: P15DF - High pressure fuel system, cold start: Pressure too low. I tried to clear the code and it would not clear. Okay. So the next day I start it up with a bit of the usual difficulty and drive it around. I then check codes and it shows a misfire on cylinder 1 and 2, and the low pressure code. This time I push clear and, boom, they're cleared. Those codes have not returned since. I talked to a MINI service adviser at my "local" (70 miles away) dealership and he said if the codes cleared, just roll with it, but he wasn't sure what the deal was with the startup sputtering.

I'm getting quite frustrated with the state of the car and how convenient it is that I'm getting all these issues after only 2000 miles. On top of this, I'm getting the brake light and car-on-lift symbol on startup. From what I understand, that means worn brake pads so basically the previous owner is really irking me now.

Anybody have any idea what could be causing these startup/sputtering issues? In my mind I'm convinced it's either carbon buildup or the obvious HPFP failure (since the code was for cold start fuel pump pressure). Any advice on things to try or troubleshoot would be very much appreciated. Thank you.

edit: I have also tried using B12 on a couple of different tanks of gas, but it doesn't seem to have helped. It's actually gotten worse since then, but I'm guessing it isn't because of the B12.

 

Almost sounds like the HPFP is starting to fail with a code like that.

Given the sputtering, it's definitely something fuel/ignition related. How many miles are on the car?

 

It has 72,XXX miles.

I suppose a HPFP failure is cheaper than carbon buildup, but man that's still really frustrating, especially considering MINI hasn't extended the warranty on the '11 and '12 models because they allegedly "fixed" the issue when they very clearly did not.

 

Sounds like the previous owner didn't want to do the known repairs or something.

Check w/ your dealer or run the VIN check to see if your HPFP is covered and get it fixed. Chances are, that's what's causing your start-up failures and misfires.

Ultimately, get it looked at- if not at a MINI dealer, a reputable one. I always had to drive 8 hours to get to a MINI dealership who blew ***** when I was in ND.

 

Sounds like a HPFP. I don't know that there is any good way for a shadetree mechanic to diagnose the fuel pump since you're dealing with some pretty ridiculous fuel pressures. Take it to the dealer for a diagnosis and maybe they'll good will the HPFP replacement?

You don't say how many miles are on the car but a carbon cleaning probably wouldn't hurt either. Also, check the water pump and oil feed lines to the turbo as they are common failures.

Also, why is your failing to check the wear of the brake pads before you bought the car the previous owner's fault?

 

72k, as I said above.

My frustration wasn't at having to replace brake pads. That isn't a big deal at all as I can do that myself in a pretty timely manner. My frustration was directed at how the previous owner appears to have just traded it in when it was time to do all these maintenance things/repairs (battery, brake pads, HPFP problems), so I'm hit with all of them at once. It was just an off-hand comment on my frustration with what he did there.

 

Pretty normal, actually.

Most car owners are prompted to jump into a new vehicle when expensive work is on the horizon.

 

I've finally gotten a service adviser to call me back again and I've scheduled a time to take it in to be diagnosed. I suppose after they tell me my fuel pump is on its way out, I'll take that diagnosis to MINI and see what we're going to do about it. Thank you for the replies, all.

 

Hopefully they'll take care of you!