The Yo-Yo Chronicles
#751
#752
#755
#756
#757
Originally Posted by Ryephile
Yes, the CEL may come on with the bypass valve zip tied. I experienced this a couple times, however it is not cause for concern, it's just the computer finally realizing that "something" isn't "stock". The light will go off after three ignition cycles of "normal" operation (which doesn't mean you necessarily have to cut the zip tie), no need to go to the dealer for a reset. I believe the CEL is from the front MAP sensor not reading according to a data table (due to the valve being shut all the time), and this causes a freak-out alarm. Honestly, not a real problem, though the light is annoying
Remember: This is still a temporary "grassroots" fix, and not a permanent OEM solution. Of course, if you want to do either of the fixes, you're responsible for your stuff.
Motor-On,
Ryan
Remember: This is still a temporary "grassroots" fix, and not a permanent OEM solution. Of course, if you want to do either of the fixes, you're responsible for your stuff.
Motor-On,
Ryan
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).
#759
#760
Join Date: Mar 2005
Location: Newcastle, England, UK
Posts: 429
Received 0 Likes
on
0 Posts
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
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
#761
#764
Join Date: Mar 2003
Location: Fayetteville, NC USA
Posts: 1,562
Received 0 Likes
on
0 Posts
#765
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?
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?
#766
Join Date: Mar 2003
Location: Fayetteville, NC USA
Posts: 1,562
Received 0 Likes
on
0 Posts
#767
Originally Posted by Moorlockx
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?
#768
Join Date: Mar 2003
Location: Fayetteville, NC USA
Posts: 1,562
Received 0 Likes
on
0 Posts
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.
#769
Add another 05 to the list...
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?
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?
#770
Join Date: Aug 2005
Location: SoCaL (Agoura Hills)
Posts: 3,902
Likes: 0
Received 2 Likes
on
2 Posts
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
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
#771
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
https://www.northamericanmotoring.co...ad.php?t=38268
#772
Join Date: Aug 2005
Location: SoCaL (Agoura Hills)
Posts: 3,902
Likes: 0
Received 2 Likes
on
2 Posts
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.
#773
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
Does anyone have any recent updates on what MINI is or isn't doing?
Terry
#774
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.
#775