Seen misfire codes anywheres from just two cylinders to codes for multiple misfires due to carbon buildup. The carbon stays red hot igniting unspent fuel when the cylinder is not supposed to be firing.

If your MINI has never had that service done, or checked it would be at the top of my list. And assuming you have already replaced the HPFP for potential fuel issue, and that you have already moved onto spark, checked the plugs I would do a CB check of intake valves.

The intake manifolds on your engine are not like the earlier cars. It's made of plastic and has 4 orange color gaskets

Some CB info:

 

Thanks for the info! I'll definitely check the intake valves for CB.

Does anyone know if I need a specific OBDII reader to read and erase all codes?

 

I clear the codes with a basic bluetooth OBD2 connector, and the free Torque app. The warning light doesn't seem to store a code for me. That's totally weird to me.

I know for a fact that my car has some serious carbon build up on the valves. It surprised me when I saw it. Perhaps that's my issue too. Is there a way to DIY this instead of paying for this walnut blasting? I don't doubt this could be the issue but it is odd that there is no code that sets to help with diagnosing this reduced power light.

 

Alright so the initial problem (car not starting) was fixed by replacing the HPFP. The problem that it was having after (lack of boost; "limp mode") was caused by a boost leak in the vacuum to the wastegate. Took it to the shop to diagnose and fix. Drives all good again I'll post a picture tomorrow of the notes they gave me! Thanks for all the input guys

 

apparently boost leak is a common cause of this problem, it's just a matter of where the leak is. Mine happened to be a leaking vacuum hose to the wastegate.

 

glad it is all fixed, at least you have the new diverter valve now so you can turn up the boost (if you haven't already) muahaha!

 

hahaha one day for sure

 

Thanks for the follow up. I've just pulled the intake manifold, dreading having to clean these intake valves. I'll apply some pressure to this wastegate vacuum line and see if I find something.

 

You may have to change the manifold gaskets, but not necessarily. The set of 4 is pretty cheap to have on hand or change out anyway, though. I've always thought that changing them out was easier than putting everything back together and then figuring out you needed to go back and put them in anyway.

I would think that misfires (which can be caused by carbon buildup on on valve heads/intake ports) would show up as random or specific codes. But based on your trouble description, I'm wondering how you can have the half engine trouble icon without any codes. have you tried disconnecting the battery and letting your MINI sit in the corner a while, and contemplate her transgressions? That's what I do with my kids. Maybe she'll tell you what's wrong after a little time-out.

Your ECU should be trying to tell you what the problem is, or at least pointing you in the right direction.

 

Interesting, Have you measured the fuel pressure at the injector rails? I know you replaced the HPFP but this will verify that the whole fuel system is ok. Do you have a Boost gauge to measure the performance of the turbo? If not, it would be a good investment. If that all checks out then, the fuel, air, and spark(new coil) can be eliminate from the possible list. After this do a compression check just to verify that is good. After all this then get then check the valves for carbon build up mentioned by "ShadyCoop". Do all easy checks first before you start a deep dive.

 

See Pelican Parts walk-through on their website on how to DIY. You can get everything you need for about $200. PM me if you need pointers.

 

My mini is all good now! (see previous post) but my mechanic said that I needed a BMW/MINI specific code reader to read the codes that I was getting, which is why I couldn't read them with my basic code reader. He pulled the intake manifold for me and said that carbon isn't a problem as of yet. Thanks for the reply though!

Tyler

 

oh if only it was that easy. i drove around with the "glass half full" error for almost a month replacing coils one at a time (should've just done all four and been done with it), the diverter valve, then finally the HPFP (i had recently changed plugs so i knew they were okay). HPFP fixed the problem. No codes were ever stored, which is why I saved HPFP for last and why I didn't go to the dealer since all they do is scan codes and replace parts based on results.

 

Yep, we have a DIY on carbon clean up here: http://www.pelicanparts.com/techarti...n_Cleaning.htm. Still a very effective method.