I have a 2010 Cooper S that under wide-open throttle I feel a little bit of boost loss, it will spike then pull back then spike then pull back etc....

My first thought was a bad diverter valve but just wondering what else I could check.

 

What psi is it spiking to?

 

Gear? conditions(ambient temp)? ect..


+1

 

No boost gauge and I did not have my accessport plugged in.
I guess a better description is it began surging. Foot down, the turbo spooled then seemed to pull back and it surged like this and woudn't maintain full power.

 

it was about 83 deg, 5th and 6th gear cruising at highway speeds, level ground..not more than 100 ft above sea level.

 

Mine is doing this too.
I have 2007 MCS R56 with the MCS K03 on it.
52K Miles
It spikes to max boost (12 on Stage 0 and 18 on Stage 3) then surges BAD (Drops to 0 and stays there) then drops boost completely until you hit 75% throttle then surges and does it all again. I mostly see it when accerating from a dig. It is also common around 4k in Gear 1,2,3, and 4. On the Alta Stage 3 it was so bad it made me spin out and loose tracton.

It should be noted that I am getting GREAT vacaum (26), but boost is floppy. It has been doing this for about 4 weeks and I even tried clearing the ECU Learning, but it keeps doing it.

List of Mods
NM Discharge Pipe
Stratmosphere Exhaust
WMW diverter lve
Defendrs of Speed Inake
Alta Hard inlet pipe
BSH Oil Catch Can
AEM Boost Gauge off NM Boost Tap
Mini Mania Intercooler Air Diverter with dual washer sprayers hooked up to spray every 4 sec for 2 sec.
Running Shell 93 VPower since the day I got it.

Things I have tried to fix this
Cleaning Inake
Emptying Catch Can
Changing Oil
Applying a Stage 3 tune (Same thing except worse)
Removing Neg terminal and letting it sit

 

You're hitting the 22psi boost cut. Known problem on tunes, the stock map sensor cuts boost to 5psi when u hit 22 for safety reasons. The reason you're spiking to 22 is the ecu compensating for the heat/iat's by using more boost to try to hit the same target power, thus load spikes, which requests more boost, next thing you know you're at 22psi and it goes to 5

 

Check your diverter valve too and see if the diaphragm is ripped. Check on drivetrain forum for others experiencing this... If you're on r access port this shouldn't really be in stock problem fyi

 

I don't think you read my post. It was doing it before the tune, and I know it never hit 22psi. (AP and gauge confirmed) I did know about that little issue. Also, it isn't dropping to 4 or 5 it is dropping to 0 or Vac.

I will check the Diaphram, cause that was my next thing I was going to check. A div valve is cheap, so I am hoping it is that. Got logs coming just in case.

 

http://home.grics.net/irish4/1/log.xls

 

It is a stock problem because the car started doing it before the Accessport was applied. It did it without a tune, so I would concider it a stock problem. I did replace the WMW diverter valve with the stock BMW one and it did not help. The valve was intact, so I just pulled it and tried the BMW one for ***** and gigs. The worst surge appears to be after I shift and build boost right around 14. I have two more logs coming that have more data in them.

 

Sounds like a lot of diagnosing... I would have started with checking the D/V then doing a boost leak test. Hope that helps.

 

I'd be curious to know what this turns out to be as well, as mine has started doing it, but very intermittantly - the rest of the time it seems to run normally. Also only seems to happen in the upper gears under a hard pull, like going up a long hill or merging onto the highway, mine's done it in third and fourth too. My car is a dead stock 2009 Cooper Clubman S automatic. It happened a couple of times while at MITM, but it's done it before down here at sea level too.

 

Update: I just ran it though all the stage 0 (Stock) though 3 maps from Alta and did 2 passes 0-100 then coasting. I just sent them all the data. Mine isn't doing it bad on the stock tune as it was a week ago, but still every once and while. I changed my charge pipe to a NM one today hoping it would fix it. No such luck.... I have more data available if someone wants to take a crack at it.

http://home.grics.net/irish4/R56.zip

 

Any news on your boost issues? Your data logs must have been generated in AccessPort, yes? The breadth of data types is terrific!

 

I took a look at a couple of your logs and one thing that seems common is the really high IAT's. I'm no expert but this seems really high compared to ambient temps.



Before I added water/meth my car would do the same thing (drop boost during high engine loads), although even then I wasn't seeing IAT's that high. The ECU will retard timing when inlet temps get high to prevent detonation / preignition. Now this might not be your problem, but I don't think it's helping.

For comparison, here's a recent log from my car.



Hope you solve your issue, good luck!

By the way, I just noticed you have the Mini Madness IC air diverter / sprayer. Was it spraying during all these test runs?

 

You could be hitting boost cut if its going anything above 21

 

I noticed 1 things with both members. No upgraded FMIC.

I'm guessing:
boost leak
ripped diaphragm
heat soak

silhouette88
has Helix FMIC no issues and good IAT, along with Water/Meth not sure if it was used in his plot though.

 

Yep, that graph was with the water/meth at approximately 50% methanol concentration. I'm upping the concentration to 75% this weekend and could post an updated chart if anyone was interested.

I still wonder about that mini madness IC sprayer. It doesn't look like it's helping him too much...

 

The water/meth injection has the helpful effect of lowering MAP levels for a higher mass of air moving through the engine. It's a good workaround to that ~22psi sensor limit.

 

It is not the FMIC, I know that. I did not do one of these pulls with my meth sprayer/Prechiller on. IT chills the meth/water to 19F and then sprays it on the intercooler. I did not have it running because it was another variable to rule out. (604watts of TEC coolers to supercool it down on a timed spray)

It was actually not heat, Boost, or D/V related. The ECU or Main harness is toast. It was dropping boost because the ECU was choking. My ABS computer has been acting up for months and it has been going on since I have had the car. Saturday night it went bonkers. It would not idle below 1k and it was surging like crazy. The wipers moves, the transmission shifted randomly, the throttle would not respond, the steering wheel did nothing, and the LCD was a Christmas tree. The only thing that was working 100% was the brakes. I am getting it fixed under warranty, but it is going to be a ***** worth of time. I will let you guys know.

Next year I plan on going K04 Hybrid, Helix or Alta FMIC with CO2 sprayer, Meth Injections with super chiller, and a stage 3 matching tune. I hAve never really had my Mini at 100% technically so I am excited to get it back.....

 

Its been awhile but yet, I'm seeing 22psi spikes under WOT.
I am stock FMIC, stock airbox, stock diverter.
Only mods are RMW tune via AP and cat-back exhaust.

 

Some development on this, Two things are happening:
1. Without enough oil or the right oil the Cam will not work properly and cause this. (not the issue but just FYI)
2. Bad VAC line. I plan on getting this checked out ASAP, but prob wont be 100% addressed till spring when I move to the K04. As for the FMIC, those numbers were without the sprayer running. I ran it last night and the IAT was not above 50 because it was 37 when I was running the car.

Also I moved to the Forge DV (the new one) and this got a little better, but still happens.