Mechanics

HESITATION AND**********

2008 Mini Cooper S • 4 cylinder FWD Manual • 25,000 miles

Enter yoMy car is a 2008 MINI John Cooper Works. The car runs ok when using the standard ECU tune, although there is a hesitation problem when going from 1/8 throttle to part throttle. When I upload the ECU tune from a popular vendor, which has run problem-free on many many cars identical to mine, the hesitation problem is exacerbated, and the car is not as fast as other cars with the same tune. I have tried other tunes from the same vendor, so I know it's not the tune, and he also is very sure that it isn't the tune. I have done several datalogs, and my tuner says that the car is retarding timing by about 5-6 degrees. My boost curve is flat and exactly where it should be. Fuel pressure seems to be ok as well. The car is difficult to drive and is******.

My brother has a 2010 MINI John Cooper Works, so I have traded a few parts with his car to see if anything on my car is faulty.

I have:

changed MAF sensor
changed both MAP sensors
changed the precat 02 sensor
changed the diverter valve
changed the pressure converter on the inlet manifold
changed the spark plugs
done a complete carbon cleaning of the inlet valves
done a smoke test to check for vacuum leaks,
probably a few other things that I've no doubt forgotten.

None of these things has fixed the problem

If you would like datalogs or any other info, my email is elietalj@gmail. Com

Thanks
Elie
ur question.
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Etalj
July 4, 2011.



What about the injectors and throttle body, have they been cleaned?
If the ECU is retarding the ignition under acceleration, the ECU is seeing a reason to do so. Possibly high exhaust gas temp. Has the computer stored any codes? Try using a higher grade of fuel to rule out fuel quality issues, including higher octane. Some "tuned" engines are picky when it comes to fuel grades and quality.

Rivermikerat
Jul 4, 2011.