Hi there. My wife has an '09 base model Mini. We've enjoyed the car very much. Recently, the car has had trouble starting on cold (below freezing) mornings. It'll crank fine, so I know it's not a battery issue, it just cranks for 5+ seconds prior to starting. It also has a low-RPM, medium load hesitation. It's very brief, and usually occurs when putting around at <2500 rpm, then giving the car gas to start accelerating.

I suspect a fuel problem is the cause of both of these issues, so I hooked up my pressure gauge to the fuel rail this morning, but couldn't reproduce the issue. It shows 52psi and has held that all day. I left the gauge hooked up and will let the car sit overnight to see if the pressure bleeds down. I find it strange that the hard starting would only be an issue in the cold though.

In the mean time, any other thoughts? I'd prefer not to buy a new fuel pump if I don't have to. I'll plan on replacing the fuel filter as that seems like a good idea regardless, but I don't think this would cause the hard starting issue.

 

It's not a "base". It's a non-S.

 

To-MAY-to, to-MAH-to. Base, non-S, Justa. They all get the idea across.

OP: No idea what could be causing your problem, but here's a free bump.

 

Have you had the thermostat looked at? Does the car have a check engine light illuminated? Stored codes?

Spark Plugs? They are due every 100k miles on the N12 non turbo engines, but we have seen them fail in under half of that.

A problem with the electronically controlled thermostat is the sensor will fail and see either extreme cold or extreme heat and keep the car from starting or cause a hard start.

Thermostats on the N12/N14 engines are rather common failures.

 

No CEL, I'm not sure if there are stored codes. I'll have to check the plugs. After leaving the fuel gauge on the rail for two days, it only bled down from 52psi to low 40s and still had a hard time starting. I'm gonna say the pump is probably not the issue.

I'll have to read more about the thermostats. Thanks.

 

Let me join in here too with a similar complaint, as my N12 engine has just now begun to give me starting troubles when it's left out in really cold weather. It will crank for up to and beyond a full minute before reluctantly starting. Not so if it sleeps in its heated garage. I've also noticed an occasional sputter at idle as if a plug were fouled. The original plugs are 7 years and 70k miles. No engine light goes on. I see this thermostat sensor as a possible lead.
Could my symptoms match that diagnosis?

 

I would definitely change plugs if they are original

 

2009 Clubman S. Was stranded at airport after sitting for a week. Car would start, drive about 20 feet, and then stall. Car eventually started after warming up and was driveable but sluggish. Turned out to be fuel pump. There are two no the car. Was replaced under warranty and is now covered to 100K/10 yrs. There are two so if one is working it will run on a single pump.

 

The N12 non turbo engines still use port injection, not direct injection, so no need for the HPFP.

On the turbo engines, when the HPFP fails hard starts, no starts, low power, misfires, and a CEL illumination will be present. In many cases when a low pressure pump (intank fuel pump) fails there is no bypass for fuel to be drawn through so the car refuses to run.

 

A followup on my freezing days starting troubles-
I did change my spark plugs, not knowing what else to try, and the long cranking vanished. It starts right up again. My plugs looked almost normal, so I thought I may have misspent that $250, but ever since then (about a week ago) the Mini starts up like new again. Last night it sat out at below 0ºF and...vroooom.

 

Change plugs and also check the throttle body for freeze up in cold weather due to moisture residue in the intake.

 

'13 base cooper here. car just doesn't seem to like starting up in the cold. it's not a daily for me so i avoid it. probably is just the ecu trying to warm up the engine