R55 Cooper - Stalling / Lumpy Idle

[DaveyBoyWonder]

Morning all. After praising the reliability of my little Clubman, its been causing me a bit of grief in the last week typically.

About a week ago it was down to about 30 miles range left so filled it up (at a BP garage, not the local Tesco which I do normally use). Drove about 6 miles, stopped to nip into a shop and when I came out again it stalled starting it. Did it a few times until I put my foot down a bit when starting (never normally need to touch the accelerator when starting) and it fired into life... then conked out again at the next roundabout. Same starting procedure again, did the same thing at the next junction. Parked up for a few hours when I got to my destination and then drove it home later in the day with zero issues.

Initial thought was dodgy fuel and thought no more of it.

Anyway, wife driving home from a hospital appt yesterday and it died on the approach to a large roundabout on the A64 where two BT engineers pushed her to the side of the road. Didn't bother with the RAC so I drove straight out to see if I could get it started/tow it home and managed to start it again straight away with a bit of throttle and the car was driven home.

Plugged in and getting a few error codes:
2845 VANOS, exhaust: actuator movement
2B68 Air-mass flow, plausibility
2D9B Knock sensor, signal

From reading up on these, they all seem to be kinda fuelling/air related I think and there has been mention of replacing the MAP sensor which will fix it. But if its dodgy fuel, the same will happen?

Anyone else come across anything like this and managed to resolve it? Thinking about trying to get the tank drained and cleaned and new fuel in it? Or just give it an italian tune up and then throw fresh fuel in it (not from BP!). Any additives I can put in the current tank? Its about half full now...

[CoolHands]

I would make sure battery is fully charged / good condition (can cause lots of errors), clear errors, observe. High pressure fuel pump is a potential cause - have a read. I wouldn’t clean tank / lines that is extremely unlikely imo

[DaveyBoyWonder]

CoolHands said:

I would make sure battery is fully charged / good condition (can cause lots of errors), clear errors, observe. High pressure fuel pump is a potential cause - have a read. I wouldn’t clean tank / lines that is extremely unlikely imo

Funnily enough, changing the battery is definitely needed so I'll get that changed first and see what happens.

[CoolHands]

Yeah they can screw a lot up. If it has stop start you need the glassfibre Matt (AGM) type, not regular lead acid. Beyond that I think high pressure fuel pump is next on the list. This place is good for branded batteries https://www.mdsbattery.co.uk/

This guy reconditions fuel pump 789mikea https://www.ebay.co.uk/itm/BMW-Mini-N14-N18-1-6THP... although I haven’t used myself as haven’t needed too.

[DaveyBoyWonder]

Quick update. New battery fitted and coded and keep my fingers crossed on the drive home - conked out 6 or 7 times in a 5 mile drive, always when the revs drop (sitting in traffic, mega slow speeds etc). With it being an auto its more difficult to keep the revs high in these situations.

Any other suggestions before I just book it into the garage or throw a lit match at it and buy another boring but massively reliable mk5 Golf GTI?

[rigga]

Code reader and monitor the fuel rail pressure, sounds like the high pressure pump is failing, simple obd2 dongle and torque app will work

Edit
Should be around 700 psi on idle, I monitor mine with along with other readings

Edited by rigga on Friday 9th April 13:26

[DaveyBoyWonder]

Cheers rigga - HPFP sounds like another potential cause. I've given up with it and am sending it to the garage on Tuesday and just telling them to fix it...

[DaveyBoyWonder]

Quick update for anyone stumbling across this in future - seemed like it was the oil being too low. As simple as that. I'd read the oil a few weeks ago but as anyone will know with a Gen 2 Mini, the dipsticks are awful to read and I must have mis-read it. Apparently the earlier Gen 2s are well know for liking a drop or 10 of oil so I need to keep a closer eye on it! Great to be back in the little thing again though.

[mike9009]

I had an R55 MCS and it would use a litre of oil every 700 - 900 miles. It was worse than my Dad's Allegro!

Do keep a close eye on the level as I think running it down has been linked to timing chain issues and the death rattle.......

Mike

[Huntsman]

rigga said:

Code reader and monitor the fuel rail pressure, sounds like the high pressure pump is failing, simple obd2 dongle and torque app will work

Edit
Should be around 700 psi on idle, I monitor mine with along with other readings

Edited by rigga on Friday 9th April 13:26

Is fuel pressure really 700psi?

[DaveyBoyWonder]

I'll stick an update on this - been keeping an eye on the oil levels and whilst it is being used, its barely dropping which has set my mind at ease a bit! I've also done the dipstick mod to file a flat edge on the metal bulges at the bottom of the dipstick. Takes a minute to do and makes a massive difference in the ability to get an accurate reading.

[rigga]

Huntsman said:

rigga said:

Code reader and monitor the fuel rail pressure, sounds like the high pressure pump is failing, simple obd2 dongle and torque app will work

Edit
Should be around 700 psi on idle, I monitor mine with along with other readings

Edited by rigga on Friday 9th April 13:26

Is fuel pressure really 700psi?

On idle yes, then increases as the revs do, it's a high pressure fuel pump and the engine is direct injection.

[Huntsman]

rigga said:

On idle yes, then increases as the revs do, it's a high pressure fuel pump and the engine is direct injection.

Thanks. Everyday a learning day.