Hello everyone

I'm the proud owner of a 2011 Mini Cooper S R56. Around a year ago my car started having "Hard Start" problems.

By this I mean: quite randomly, it would take it anywhere between 5-10 seconds to actually start the engine.
No other symptoms at all. IDLE Engine sounds great, whenever the turbo kicks in I've got full power, and the car never actually failed to start (it just takes it longer to kick in?).

My mechanic suspected the low pressure fuel pump was bad, so I got it replaced. Problem is still happening =(

The problem appears to be that the fuel pump doesn't pre-pressurize the fuel line neither when I unlock the car, or place the key in the FOB tray.
So essentially, you push the start button, and there isn't much oil in the fuel line, which causes a hard start (as far as I understand).

Any kind of leads, help, absolutely anything would be more than welcomed.

Thank you all in advance!!

 

Are there any related error codes?

I'm asking because my non-turbo LCI occasionally also requires longer cranking (but fires immediately when it does, runs perfectly fine at all times and does not throw any codes). I suspect the Activated Charcoal Filter to be the culprit (i.e. being saturated) since I have overfilled it several times in the past.

According to a fellow forum member (on NAM or a german MINI forum, I don't remember), the car will periodically try to start using the fuel condensated inside the activated charcoal filter assembly. If there is no liquid fuel there (because the filter is worn out) it will switch to the regular fuel supply line after a certain time (causing the engine to fire immediately upon doing so).

Please note: I have not been able to verify the above information myself. The only possibly and remotely related information I have found about this so far is the following text within BMW TIS, quote:

"Blowing out activated charcoal filter

The fuel tank vent hose is connected to an activated charcoal filter. Vapours from the fuel tank are collected in the activated charcoal filter. The activated charcoal filter is connected to the intake manifold by a pipe. A fuel evaporation control valve is fitted in this pipe. When the fuel evaporation control valve is opened, the vacuum in the manifold draws in fresh air. At the same time, the fresh air blows out the fuel vapours collected in the activated charcoal filter."

 

I'm afraid there are no error codes associated, which makes troubleshooting this super hard.
I'll check on the charcoal filter, perhaps it's an easy thing to replace?

Thank you for the tip!!!

 

 

Unfortunately I've checked with the mechanic, and that filter was already replaced as well =(

Thanks a million George!! I'll keep on digging. Eventually, something's gotta give right?