Nope, I'd put money you tied it OPEN, not closed I accidentally tied it open once too - doesn't allow any boost, the car can't get out of its' own way!

 

DOH!
Hmmm...isn't the idea to hold the vaccum plunger 'out' and not 'in'? What state is the butterfly valve at when the car if off, because that's where I zip tied it. Am I supposed to turn the bypass valve 90 degrees and then zip tie?
Hmmm.....
make sense?
Cheers
Skottoman

 

Tie the BP so the plunger is against the adjustment stop. That closes the valve as far as it will go.

 

Im sorry, i just do not feel like reading all 33 pages of the thread, but how do you acually fix the yo-yo problem?

 

You have to be kidding!!!!

 

Lazy Guide to this thread:

Post #1 - the problem described
Page 6 - How-To's for both Ryephix's - pictures included, yay! :smile:

 

Recently, I experimented with disabling the bypass valve to avoid the 0-5 psi oscillation. It worked, but as you found, it set off a fault code for the upstream MAP. It looks like the upstream MAP sees a min value of about 50 mbar lower pressure with the bypass tied than with it operating in the normal manner.

Thinking about how short the distance is between the bypass valve and the vacuum source that operates it, I tried a different experiment today. I capped off the bypass valve's vacuum nipple. Then, I put in another Tee where I had tapped into the FPR's vacuum line for my boost gauge. I ran a vacuum line from that tee to the bypass valve.

So, now, instead of seeing the same type of vacuum as the upstream MAP, the bypass valve diaphragm now sees the pressure as seen by the downstream MAP. The result is remarkably similar to tying the bypass valve shut. No oscillation at all in the 0-5 psi range. I didn't notice any elsewhere either. I plan to install a check valve to prevent the bypass diaphragm from seeing boost.

I'll do some testing/logging to see how this works out, but for now, in 5 minutes time, the oscillation is definitely gone, the bypass is definitely open at idle, and less than $5 is missing from my wallet (Tee, vacuum cap, hose).

 

Last night's snowstorm interfered with my logging, but the oscillation is definitely gone and no CEL!

 

I finally got the Ryephix BPV in and it works as advertised. Much smoother around 3-4000 rpms where I spend alot of time driving here in town. Many thanks to Ryephile!


Cheers,

 

My first post ...wow !

Ive been reading this over the past few days and its made quite interesting reading. We over in the UK have heard of this Yo-Yo`ing but software updates seem to be the way to go over here to stop it doing that kind of effect, so seeing that the boost valve is causing this is making me quite shocked

And yes im shocked that eaton are suppying these valves that dont shut off fully! My car before the MINI was a POLO G40....1.3 supercharged 170bhp and the valve for that always closed off fully and once opened it used to blow off to the atmosphere with a woooosh type sound....surely if you disconnect the pipe from the bottom of the Boost valve, air would be heard rushing past the valve while on WOT thus proving there was a fault instead of dismantling it all to find it out ?

Ryephile...u seem to know your stuff matey and wish we had more people like you over in this neck of the woods so to speak

 

I have a brand new 2005 MCS, and it has the YOYO and the HICCUP and the cold IDLE problem. Had it for about a week and it is at dealer this am.

 

Well, The dealer had it 2 days and they cant "reproduce" the event - I told him I would drive it and show him . Bottom line they dont have a fix yet.

 

You can add mine to the list of Yo-Yo cars.

TD57047 08/02 (but only after the v39 software was installed)

 

Add mine to the list too, after v.39 was put in. I knew I should have never let the mechanic talk me into doing the upgrade!! The car was running near flawlessly for almost 30K miles until this was done.

I'll have to get the #, but the build date is 10/02.

 

I think this may be what I noticed when test driving an 05 MCS. In different gears while accelerating, I felt like there was a slight period when the engine was bogging down or hesitating to keep increasing speed.

Initially I had wrote this off mentally as insignificant or something that would go away as the engine broke in. But now, it seems like this is a widespread issue and it had put a damper on my wanting to buy an MCS since all these ECU updates and other fixes don't seem to be solving the problem.

How many 05 MCS owners haven't had yo-yo issues?

 

Got a techie question.....as my car didn't really have the yo-yo before v.39 was put in, can it be uninstalled and revert the car back to it's original settings?

 

Unfortunately, no you can't. I had v 31 or whatever for 50k+ miles. Everything was fine. Had none of the possible problems. They gave me the ECU upgrade for the recall (even though I asked them not to) and I "caught" a yo-yo that made the 2k RPM range pretty horrible. Thank god the GIAC ECU helped it tremendously. It still does it somewhat but it's liveable. What's even more unbelievable is my brand-new 2005 Mustang GT with throttle-by-wire is incredibly smooth and FORD has had only ONE ECU version for the entire year! No cold start problems, no yo-yos, no bogs, no reverse yo-yos, and no recalls. And it's the first drive-by-wire in a Mustang. I still absolutely love my MCS but BMW/MINI sure did some shoddy engineering on this car.

 

Thanks for the reply. :smile: Somehow, I figured that would be the answer. Wish I had realized what had happened before I talked to MINI USA on their follow-up call from the service. Not that it would have done much good with the number of complaints they've already gotten on the problem.

 

WOW, that took me all day to read! LOL

I've had the yo-yo from day one but thought it was just due to driving style until I started to skip gears to see if i could incread my gas mileage. Then when I stopped and started going thru the gears normally and it started doing it again i knew something was up...
I know this is a shot in the dark but any word on a fix yet?

 

Most of what i've read in this thread tells me that RyPhix #1 (Zip Tie Method) will have cause no damage to the engine or associated systems. Then again, most of the posts are over a year old. Does anyone have an update to whether or not tying the bypass valve closed will cause any damage?

That being said, my check engine light turned on because of the fix, and i've noticed the engine seems to almost backfire every time I release the pedal quickly, say for a shift.

Also, write me down for the yoyo, I don't have my vin handy, but i've had it since day one. RyPhix #1 worked for me

 

I don't think tying the bypass closed will cause damage, but you will likely have a fault code, and your mileage will be worse. Give the VGS a try and see how you like it:

https://www.northamericanmotoring.co...ad.php?t=38268

 

Since I don't posess the mechanical know-how to dismantle much of my engine (which has many non-stock parts... including a water to air intercooler which i'd rather not mess with), I was thinking of just getting the Detroit Tuned bypass valve with the stiffer spring, and having it installed at an indy shop.

 

The last post to this topic was September of last year. What has happened since then? Why has the issue gone silent? Are we just waiting for MINI to issue a "v.40" fix? I bought my 2003 MCS in September of last year and noticed that it had the "stumble" effect, although I didn't know that's what it was until I started reading this post. I took my MINI in for service a few weeks ago and they did the recall ECU "upgrade" and, whoa!, now I have the yo-yo effect! The stumble is gone, but I got yo-yo in return! When I mentioned it to my SA at Global MINI in Atlanta, he said he had no solution other than to wait for MINI to find a fix. I'm guessing MINI is going to try to wait us out, that is , let our '03/'04 & '05s get so "old" that they can just write the problem off to history. Personally, I would be interested in re-visiting the class action suit approach.
Does anyone have any recent updates on what MINI is or isn't doing?
Terry

 

They're throwing out the budget and trying to get the PSA engine to stop blowing head-gaskets, that's what. For all practical purposes, fixing drivability problems with the Tritec is old-news to them. Try moving the vacuum source for the bypass valve, or changing the return spring, both are good, if different ideas.

 

This thread is really old and shuffled away but I was wondering. Is there somewhere I can get the spring used in the DT BPV ? I really dont feel replacing that spring is worth $125 and would really rather do it myself...