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I have a 2011 R56 with an N18 motor and a 2009 Clubman with an N14 motor. Recently the 2011 quit starting acting like it is starved for fuel. I tried for a bit to figure it out but ended up sending it to a trusted mechanic that I use when I can't figure things out myself. He has replaced the fuel pump in the tank, the plugs, the coils and it still won't start. He says it's trying but it just won't go. Scanner says fuel rail pressure is low, but wouldn't that be expected during cranking? Fuel is being delivered to the HPFP which is only about 1.5 years old and that is looking like the next move... not cheap! Is it possible that trying to start the car with insufficient fuel feed to the HPFP has ruined it?
More info... not long after the 2011 went down, my 2009 started taking more and more time to start until it too now won't start acting like it is starved for fuel.
These could be unrelated misfortunes with different root causes, but prior to the 2011 going kaput I changed the batteries in both vehicles and "upgraded" them to a 70ah AGM battery that I got on Amazon - please don't judge. I've read about the JBE and the relays in there and how you need to register a new battery to make things work right and I'm wondering if/how the new batteries might reasonably be the cause of these issues.
I'm looking for some simple diagnostic procedure(s) to figure this out. Actual experiences with this issue would also be really helpful. I'm a school teacher and I can't just have them carted off to the local MINI dealership for a full run-downl My 2009 Clubman is still in my driveway so I would be able to do some simple diagnostics on it that might help both cars - IF the problems are related... HELP! TB
It's unfortunate that your mechanic replaces parts rather than performing diagnostics. Given that pump in tank was replaced, low fuel pressure at the rail is likely a HPFP failure.
I had this same issue about 6 months ago and I addressed the entire fueling system. I replaced the fuel pump in the tank, sender, and the HPFP from ebay twice...there was no resolve until I ordered a HPFP from FCPEuro which costed an arm and a leg. You will most likely need to do the same.
what is the fuel rail pressure youre getting before trying to crank
it should read around 70 psi from the in tank pump, if you have that amount of pressure then its likely the hpfp
I'd add that if your car runs fine after starting, but has to crank for too long to start, you may have a leaky injector, or other problem that allows the fuel pressure to bleed off when the engine's not running. Normally fuel pressure will be maintained for a long time (days, even) with the engine off, so your engine will fire right up. But if you have a leaky injector, it'll dribble fuel into one of the cylinders until the fuel rail has little or no pressure. Then, when you twist the key to start (or push the start button) you get no satisfaction until the fuel pressure builds up to the point the system can start working properly.
Diagnosing this is easy peasy - just turn the ignition on, but don't engage the starter. This will cause the fuel pump(s) to run to prime the fuel rail. Better yet, turn the ignition off again then on again, so the rail benefits from a few "primer shots". THEN, try to start the car as normal. If it fires right up, you know that you've got a leak somewhere that's causing your fuel system to lose its pressure.
There are several ways to determine where the above mentioned leak is, but this post is long enough already... ;-)
