Did the fuel filter on my '05 R53 at 48K miles on a hunch...I had done a 15% pulley, Dinan CAI, new coil pack and plugs and although all of this certainly made a difference in perceived go-factor I too was having a hesitation at 2500 on up to 3300 rpms...

It's not all that hard to get the fuel filter out and trust me, you will find it is coated in filth and the car will be much happier with a new one.I found the stumble and hesitation much reduced after the change.How they can call that filter a lifetime part is one of the bigger mysteries of Mini ownership.

Mad Gepetto

 

How was performance above 3300 RPM and full throttle?

It seems strange that a fuel filter would cause these issues if the performance above 3300 RPM wasn't a problem. Then again, any performance issues or hesitation, sputters, etc. are usually spark, fuel, or air. What I'm thinking is that some of the engine management and design of this engine makes the dip on any healthy engine just more pronounced on an engine where something isn't optimal. My other guess is that the dip on a normal car is there on purpose to ensure no predetonation exists at that particular RPM range. E.g., either the spark is retarded or the throttle is closed slightly or both in that range.

I've been looking around for an inexpensive remap or tune that I can purchase. Maybe that would resolve it? Anyone know where to find a good tune shop in Chicago or a chip I can buy? Maybe there's an iPAD interface out there?

 

Excellent point re the dip built into the ecu to prevent detonation, I think that is entirely likely, and it may be why so many of us find this sort of wiggly spot at lower rpm's but I also think a clean fuel filter will be less likely to create any slowing in flow available to the injectors...the change in my car was not extreme, just smoother through the rpm range and more willing to rev. The coating of grime and sludge on my old filter was shocking ( to me, anyway) on a car with fairly low miles.

Passing seems a bit better too, not long after I did the new filter I did a trip south to Los Angeles and going up the Grapevine the car just flew...most fun I've ever had going over the Grapevine, no pinging if you put your boot in it.

I can't say that's all down to the new filter, but it certainly didn't hurt.

 

If all else fails check this as my problem was a disconnected line on the intake manifold. I had no boost gauges and couldn't tell. https://www.northamericanmotoring.co...-this-out.html

 

I'm having the same issue and really hoping for answers!

2003 Mini Cooper S manual transmission
169,000 miles
Purchased car Oct 2014
(No idea how well the car was maintained by previous owners)

I have changed the following parts so far since I purchased it:
- Bypass valve
- Spark plugs
- spark Plug Wires
- Coil Pack screamin demon
- Map Sensors (All)
- WMW super charger pulley package
- Timing chain tensioner
- Supercharger inlet tube
- Belt
- Hydraulic Belt Tensioner
- ATI super charger damper crank pulley
- Megan racing EZ coil overs
- Power steering pump
- Oil pan and seal
- DDM works air intake Kit
- M7 Oil Catch Can Kit
- PCV Replaced
- Rear Wheel Hub Bearings both
- back passenger fender light bulb and electrical outlet
- Polyurethane Motor Mounts (ALL)
- Taillights Euro
- Fuel filter
- Fuel regulator
(I'm using 93 octane and Mobil1 oil)
- checked for any line vacuum leaks, no leaks.




At this point the car is still consistently having issues with acceleration from 2,000-3,500 RPM. I haven't had any check engine lights come on. I try to accelerate and it feels as if I just let off of the gas pedal on and off as I'm reaching these RPMs it's the strangest thing. What other resolution is there?

 

I know you said you checked for vacuum leaks but check out this thread as I was having the same issue on a previous MINI and it was a simple fix when I found it. I found the same issue with one of my friend's MINIs as well.

https://www.northamericanmotoring.co...ml#post3724749

 

Thanks, checked it and the plug was in the hose thought it was ok but further checking it wasn't 100% air tight seal. Got it secure and now car is running way better. Silliest little detail. Glad to see it helped! Thank you.

 

My 2005 R53 threw a P0108 code at the track this weekend after coming in from a session. I had a bit of a stumble around 2500 RPM but never went into limp mode. That began when this started. I have both a boost gauge and a ScanGauge II mounted in the car. The ScanGauge could not clear the fault, but I borrowed a friend's Actron code reader and was able to clear it. Went out for another session and noticed that the P0108 came back fairly quickly. I noted that I was getting normal vacuum/boost on the boost gauge , but a reading of -0.5 to -0.1 on the ScanGauge boost monitor and it never really moved - more like it counted down and stopped at -0.1.. Based on the instantaneous boost indications on the real gauge, and none on the ScanGauge monitor I'm fairly certain that my MAP sensor (below the I/C) needs to be replaced so ordering one tomorrow.

 

@All,
I've been lurking these threads as I've been battling the same exact symptoms for almost a year now - overall feeling of reduced power and especially obvious dip in output around the 3k rpm zone (like you lifted throttle).
I am very happy to report that following the link over to the "Drivetrain Hesitation Problem- We're Stumped- Please Help Us Figure This Out!" led me to look for my fuel pressure regulator vacuum/boost hose connection which was in fact disconnected and dangling from the intake manifold nipple it was supposed to be attached to. Connected in a minute, fired up the car, and when for a lap around the neighborhood - WOW. Best "upgrade" I've ever done (1 minute fix, free, lots of returned power/driveability). Completely eliminated the performance valley around 3000 rpm and the engine is very linear again. Feels back to the little rocket it should be and I'm very happy.

Will be on the lookout for any side effects running the car like that for so long. Hoping I didn't burn anything out at WOT, although it's kind of a self regulating problem because boost was also limited by a relatively large hole in the intake manifold pissing out pressure! (Got some sweet sweet boost back).

Hope people in this thread found a solution to their problem as easy as this was for me. I had already replaced belt, plugs, plug wires, coil pack, and was considering BPV.

Happy Motoring!