I took my 09 R56 MCS to MINI of the Woodlands (the closest dealership to me, 90 miles away) last week for them to diagnosis my "stall on cold start" issue. I had rough cold start problem together with misfire check engine light earlier this year, and got the misfire CEL sorted out by cleaning (walnut blastering) the carbon deposit on the intake valves, throttle body, and the intake manifold. The car ran immediately much smoother after the carbon cleaning, but the cold start problem kept getting worse over time. Now I have to start the car 2 or 3 times every morning to get it started. The car would just rattle and stall before the final attempt.

It looks to me very like the symptom of the HPFP failure. But dealer kept calling me saying they cannot find a fault code when they tried to reproduce the problem (start the car after sitting for hours), and they couldn't even identify the source of the problem!? I was shocked and told them they shouldn't rely on a fault code to identify a problem or authorize a warranty repair (I have one year warranty left on the HFPF). But the service advisor insisted that they need to see the fault code before they can do anything.

So what option do I have? How do I convince them to further investigate the HPFP? When I asked about the HPFP pressure he orally told me the pressures are within spec, should I believe him or ask them to provide a print out of the pressure reading? Can I ask them to swap in a working HPFP to cross checking? The bottom line is I don't want to pay them the diagnosis fee if they cannot even find the source of the problem , not to mention I have to make another 180 miles round trip to collect my car.

Any suggest or input will be greatly appreciated!

 

I had a similar problem, no code as well. I fixed it by changing my clogged fuel filter. A £20 part.

So if you have no code and it only stalls on cold start, I'd suggest you change the filter first.

 

Agreed, fix the cheap stuff first.

 

disconnect the HPFP and see if the car starts fine.

also, take a short video and show it to them. sometimes for inventory and liability they dont just replace parts because the customer wants to. oddly enough every story i hear is similar to yours. the car goes to the dealer and it behaves like it got no issues. once you take it, it craps out...amazing!!!!

 

Make sure they start the car the next day not a few hours later. Usually it would throw misfire faults. The details show the rail pressure. If its under like 5 bar its the hpfp. Chances are you do have an issue thats not the hpfp. It could be your fuel pump. If you disconnect the hpfp and run the car it will throw a fault. Then they will have the fault they want lol. They won't just replace it as MINI can kick back the claim if the mechanics notes doesn't show hard evidence that it was the issue. They can look at waaaay more info then the mechanics doing a regular scan.
If you do disconnect the pump i highly recommend doing it carefully as that connector is stupid and could break. Then they could say you tampered with it. Best way to go imo is record it.

 

I had a similar problem with my dealer verifying HPFP failure. Finally, I took it out and drove it hard --- lotsa WOT on a freeway, then returned it to the dealer for an overnight cooldown. It failed the next AM when they tried to start it. Cost me a couple nights hotel bill and some out-of-town restaurant meals, but it got fixed. The trick to getting it to fail was the hard driving before shutdown.

 

Thanks for the advice. I replaced the fuel filter and it didn't fix my cold start. I was able to set-up ISTA-D on my diagnosis computer and read out the HPFP (fuel rail) pressure. It hovers below 1 MPa on cold starts while the set-point value is 5 MPa.


I also got misfire code but no HPFP code yet. At this stage, the only piece missing is the in-tank fuel pump pressure. It has to be either the HPFP or in-tank fuel pump.

I sent my video link to the dealership, but they insisted on a code that directly leads to HPFP. Without a HPFP code, they cannot do anything, they said. I am frustrated with the dealership. I think they should have measured the pump pressures for the $150 diagnosis fee I paid them, but they ended up not showing me any hard figures and left me guessing the source of the problem, and I had to go through the diagnosis procedure myself. And even when I show them the hard figure, they still just want to see the fault code.

Thanks for the input. Do you mean unplugging the electronic connector to the HPFP? If the in-tank pump pressure checks out fine and it takes forever for the car to throw out the HPFP fault code, this seems the last resort to get the code that the dealership want? BTW, what is the P-number for the HPFP code?

I never knew this. Probably I should take my car to a HPDE event before dropping it off with the dealership?