Hey guys, new here and new to owning a mini. Been lurking in the forums for about a week trying to solve my issue, but everything just points to the HPFP.
I have an 09 Cooper S with 124,000 miles on it.
I just installed a new HPFP because I'm having the hard start/die on cold start issue. I just got the car and the guy gave me the pump and told me it'll fix the problem, but it did not. It's throwing a few codes, that have to do with misfires. But they all seem to point to the HPFP as well. I really don't want to go buy a third pump because I'm doubting that's the issue at this point.

I have a fuel filter on order.

Any other suggestions?

 

A few more questions:
Did you have these same codes before you replaced the HPFP ?
Are the symptoms/behavior exactly the same after the replacement - both when you start up and after it idles for awhile
Where did you get the new HPFP ? Brand and price ?
Believe it or not - it does happen that the replacement is bad too.

Just a shot in the dark - have you replaced the fuel filter ? But those symptoms are usually under load

 

Man, I wish I had more answers.
The previous owner gave me the pump, it was not in a box, so no idea of the brand. He said it cost him $1600...
I threw the pump on before I ran codes, so I dunno if they were the same.
I never saw the car start from a completely cold start, so I also don't know about past symptoms.
I do have a filter on order, but I wasn't hopeful that it'll clear up the issue.

 

I think you need more diagnostics - have you seen the thread below yours:

https://www.northamericanmotoring.co...re-issues.html

These can be gremlins - and a pump from the previous owner not new in box would be a bit suspect for me.

Perhaps someone else can jump in with more experience. I have only dealt with this once on a friends mini - but it took him two pumps

 

P3091 is a low fuel pressure fault. I would highly suspect the HPFP. Unless I personally knew the previous owner, I would not trust that the fuel pump he gave with the car was “new”. Sounds like he said what was needed to get the car sold.

I would get one of these pump kits on order:
https://www.ecstuning.com/b-assemble...3517588879kt4/

 

Thanks for the help guys. I really didn't want to believe it was the new HPFP. But I found info on measuring the depth of the expansion tank on the pump, so I checked that and both my pumps were over 27mm. I believe new pumps with good oil should be around 13mm. I can't believe I have 2 bad pumps.

​​​​​​I rebuilt one of the pumps and threw it on. Success! No codes, and it runs fine. I'm going to order a new pump, cuz I don't think the rebuild really works, but it was great for trouble shooting.

 

Congrats ! These pumps are demons

 

I have another question. The car smelled of gas while driving before I started working on the pump. I also saw what I believe was fuel leaking from the tank area under the rear seat. Does a bad HPFP cause a build up at the tank and possibly cause a leak?

 

I would doubt it - but could be possible. I'd guess the other way around - a non sealed tank could allow contaminants in to corrode/corrupt the fuel pump ... although filters are supposed to catch this. Might want to look at that too.

I have had these symptoms in other cars - in the last one, the journey led to a crack in the (plastic) tank. It was a Chevy Avalanche that had many years and miles. So I am sure the plastic got brittle. I have also experienced a bad fuel neck ...

If you saw fuel somewhere, I'd start there. Mop it up, get rid of all the smells and see if comes back. The problem with fuel tanks, they don't tend to leak when the gas level is under the leak, unless you are driving

 

The new pump works fine, and I haven't had any issues since it's been installed. The leak near my gas tank was unrelated, it was caused by a cracked fuel filter housing. Got a new housing and filter, and now both my fuel issues are resolved.

 

Glad you got it figured out!