Hi guys
my 2008 Mini Cooper s has an intermittent starting problem
mechanic changed fuel pump and filter
3 weeks later same thing
replaced HPFP
few weeks later same thing....so he’s given up after $2k 😡
here’s the weird part i’m Hoping someone might recognize
i can get the car to start if I undo the 12mm nut on the HPFP (is that the feed from the low pressure pump?)...crank the engine...stop it...it sprays a bit of fuel ☹️...wash it down and the car will start with a bit of a stutter and black smoke coming out of the exhaust

can anyone point me in the right direction what might cause this..i’m Waiting on an obd device to see if that helps

otherwise it will have to go to main dealer 🙄

🤞 someone might have an answer for me

cheers

shoots

This is a short version of the tale 🤪

 

Usually, you would want to read the live data like fuel pressure, ambient temp and coolant temp. There could be few areas to consider. the first would be the ground wire on the valve cover (green wire). another area would be the fuse box behind the passenger kick panel. sometime the roof leaks onto it and cause some issues. Another one is the fuel rail pressure sensor. The nut you mentioned is the acrually the outut of the HPFP that leads to the fuel rail then injectors.

 

2009 MCS - I had a bad fuel-pressure sender (located on fuel rail) which caused my indie to almost pull his hair out. Fuel pressure was consistently reading high.

We identified that it was a bad fuel-pressure sender, when we disconnected HPFP from fuel rail and ECU was still showing high fuel pressure, when it should have shown 0-psi.

These cars can be a royal pita.

Good luck,
W

 

Thanks guys
i’ll have a go at it this weekend....
Ive bought a carista obd dongle so hopefully can get some info out of this

cheers
shoots

 

I still can’t get my head round why loosening the HPFP output nut (thanks MiniToBe &#128540..cranking the engine....and then retightening the nut lets the car start 🤷‍♂️

Cheers
shoots

 

So.....just to close this thread and help anyone searching...

sent car to main dealer and they diagnosed a thermostat fault and replaced it

had the car back 4 weeks now and so far so good.....

why that would cause intermittent problems who knows...probably didn’t need to replace hpfp 🤷‍♂️

thanks everyone for their help