So a night ago I went downstairs and tried to start my Mini, it's an 03' R53 with 100K. Fresh iridium plugs and 8.5mm wires. Turned the key, the car started and then died. Did this about 3-5 times before it actually would stay on. One it was on, it would idle up to about 1500 RPM and then drop down to about 400 RPM and right before it's about to die it would catch itself and rev back it. If I try to take off, it almost feels like I am letting on and off the gas. You can hear the pressure from the supercharger igniting and letting off like it's about the take off and go! But it just feels like it gets a little gas and then lets go and then again over and over. So I left it to sit. Started it in the morning and it ran awesome. Not one problem at all. Then at night again, I was on my way home and started the car. Same thing. Made it to advanced auto parts and checked the codes because the light finally came on. I came up with this...

P1106
Manufacturer Control FUel Air Metering

P0506
Idle Control System RPM Low

P0171
Bank 1 Too Lean

Any ideas? About a month ago it read the MAP sensor was a problem but that code is gone now? Think that is it? Fuel filter? Fuel Pump? Any help would be great because this is my daily driver! Thanks!

 

Sounds like a vacuum leak somewhere in the system.

 

Agreed. Checked for broken or cracked hoses. Take a long thin hose, put it up to your ear, and listen around the engine for hissing sounds.

 

A vacuum leak will trick the car's computer into thinking it's getting more air, therby increasing the idle to compensate until it realizes that the idle is too high, so it lowers the idle back down, trapping the fuel injection into a rising and falling idle loop.

Places to check would be

rubber boots on either end of the intercooler
PCV valve hose and connection going to valve cover
the small vacuum hose going from the left hand side intercooler manifold to the fuel pressure regulator. This involves removing the intercooler to check.
hoses going to the bypass valve
gasket between the air intake and the supercharger inlet

I'd normally check for leaks using a smoke machine.

 

Wow, thanks a lot! I am going to go downstairs and look at it right now to see if I can see anything. But it's just weird how right now during the day it runs great and it only runs bad at night. Doesn't make sense at all. Unless it has to do with the humidity because I live in Houston pretty close to the water...hmmm


Once again, thanks again and any more info would be great!

 

Your MINI is afraid of the dark.

 

plug a night light into the cig lighter! problem solved

no seriously, hope you get this fixed

 

I already changed all the lights to blue! A very nice soothing feel and she is still coughing! Been outta town for the last couple days so I will check it tomorrow once I'm back home!

 

sometimes, even a bad seal on the oil filler cap can cause this too.

 

But I just changed the filter and seal last weekend, and it was doing it before and now it's still doing it. Today it ran okay but then same thing once I was leaving my destination. Going to try to look at it in more detail tomorrow!

 

No, he means the seal on the actual cap where you fill the oil back up.

 

I know its not a mini, but when I used to have my truck it was the same symptoms you are having and it turned out to be the mass airflow sensor. Once I disconnected it (worked for the truck don't know if it will work for the mini) it revved okay, once I replaced it it was good to go.

 

Hmmm, well I will have to try that once I get it back, It died on me last Friday, had to get AAA to come pick me up and take her to the shop, waiting on some feedback still!

 

Turns out my problem was my Expansion tank had a crack in it and ran my car out of coolant, and since the temperature sensor is in the top of the container, it wasn't reading my car was overheating. No idea, got a new tank, refilled it, also replaced the valve cover gasket and now my Mini is back in action!!

 

Ouch...at least it was a simple fix...the coolant tanks strikes again!! Just proves...check the simple stuff first! I really hope that was all that was wrong!

 

Yeah, the tanks are known for having cracks. The one in my old '02 MCS was replaced when it was still under warranty, and I was not even aware of the problem. Glad it's fixed.

 

Thanks! Yeah me too! The codes that came up were weird though, check them out:

P0234: Charge air pressure compressor

P1106: Pressure Sensor Intake Manifold
Input too low with engine stopped

P0271: Fuel Injector cylinder 4 input high
P1688: Electrical throttle monitoring
Level 2/3 air mass calculation error

The mechanic cleared the codes and after he did all the work the car has been running great and none of them have came back. No idea what-so-ever

 

Just say a prayer to the cylindar head gods that the deck is still flat, and the gasket is still tight!!
Those are odd codes....but if it is running fine...I would count my luckey stars!!

 

I'm already counting! Lol! Yeah, it's running better than ever too, about to do the VGS cause I ordered my boost gauge! I'm sure she will love it! A little less yo-yo is always appreciated! Thanks for all the help everyone and I'll let ya know if anything else goes wrong!

 

This seems like it's never ending! Did it again today, the car like studdered and shook in 1st, and 2nd gear. Revved it up real high and then the car went back to normal again. I have no idea what the problem is and there is no way to replicate it. It seems like when i'm letting out of the clutch to go to 1st or 2nd, and or if I punch it then it just shakes like crazy and won't accelerate smooth. Almost like it's not getting fuel or oil. Any idea would be great! Thanks!