I almost posted this in the AP thread, but it's such a convoluted mess already.


I just picked up a used AP from a member and I've had some problems and I was hoping others may have some answers.


The car is a 2010 Clubman S manual transmission with 36k miles. At this point it is bone stock and runs great with the stock tune.


I first installed the Stage 1 92 octane TPS map and it ran terrible. Gas mileage plummeted, power was non-existent, it was like someone pulled the turbo off the car.


I then installed the Stage 1 92 octane no-TPS map. This made a huge difference in how the car drove and responded, exactly what I had hoped for with the first tune. But, now I have a part-throttle stumble between 1800-3000 RPM in all gears, but especially when taking off in 1st. It's bad enough that the car jerks in lower gears and you can feel is missing as you roll into the throttle in higher gears.


I'm afraid to really lay into it if it's already stuttering at low RPM, low load.


I haven't pulled the plugs yet, but from what I can find they are not scheduled for a change until 60k and the car was running fine before the AP.


I haven't checked for carbon build up on the intake valves yet, again because the car was running fine before the AP. And this is under light load, part throttle conditions where the tune shouldn't be different than stock.


I did a datalog on the way home from work, but I don't know what the range is for any of the parameters as far as what is normal and what is not normal. I can't upload it here because of the file size but here's a link if anyone wants to look at it
https://drive.google.com/file/d/0BwL...it?usp=sharing

 

It may be a carbon issue, but when I was shopping for a tune, I stayed away from the AP because I heard too many issues like this. Couldn't hurt to clean the intake if you have a N14 engine. Could also be a failing HPFP starting to show symptoms? There is a recall on that. Does your car ever start up terribly after sitting all night?

 

I was thinking of cleaning the ports anyway, or at the very least, trying some seafoam since I already have a can in the garage. Just seems odd that it wasn't a problem before the tune.


The car starts fine in them morning. I believe it's already had the HPFP replaced. It was one of the things I checked before I bought the car in April.

 

I am having similar challenges, and am sitting at 41k. Been running the access port for some time and love it. I have had the valves cleaned once, and likely need to have it done again. It would be the first thing I would look at. BTW, When I remove the Tune, it does not happen, but there also is no great rush of power...