Engine Drivetrain 1st Gen Cooper S Installed a Detroit Tuned bypass valve now I have really bad yo yo??

The Detroit Tuned BPV is a quality piece and should not give any problems?
If your intake system is pulling outside air you may not demonstrate a rough idle.

Double check all of your work chances might be that something was simply overlooked?

The VGS theory is a interesting idea and easy to install/remove, so removing it temporarily and returning to your baseline will help solve your problem.

 

This happens to some...

some theory first.... The throttle position is set based on a bunch of stuff, but a lot of it is set based on the pre-SC manifold vacuum. The bypass valve is a mechanical link between the pre- and post-SC manifolds. Some cars just aren't happy with the changes in the DT valve.... Give Chad a call if you want.

What's happening is that the dynamics of the modified valve and the ECU maps are fighting each other. While this isn't mentioned too often now, there was lots and lots of stuff written about it 2003-2005....

There are a couple ways to fix this:

1) Go back to a stock valve.

2) Get a custom tune (you'll get more power too) that will take into account the opening vacuum level of the modified valve.

If the car was fine before and then developed the yo-yo, start looking for other wear items or small vacuum leaks and the like.

It doesn't happen at WOT because the valve is closed and you're on boost.

Matt

 

I'm with Nitro... try taking the VGS off. Then reset the ECU.

 

+1

Pretty uncommon to get any voodoo from the DTBPV...

 

IIRC the VGS mod and the DT BPV are both fixes for the same problem. The general consensus was that you do one or the other, not both.

 

Both can happily co-exist...

the DT valve changes the vacuum point where the valve closes, doesn't open as much as stock, and has a very short "transition time" so that it acts like it's fully open (as much as it can be) or fully closed, but doesn't spend much time in betweeen. (Ryan or Andy posted the actuall vacuum levels and the like long long ago.)

The VGS mod takes the vacuum pick up from a location that can have slight negative feedback in the valve set point (upstream of the SC) to a location where it uses posative feedback (to downstream of the SC) in determining the location of butterfly.

What leads to problems with none, either or both installed is that they are coupled feedback mechanisms that are indirectly coupled via vacuum levels: the vacuum is used to set bypass valve butterfly position AND is used to set throttle body position, both of which in turn affect vacuum levels. This can easily lead to instability or oscillation. MINI had a heck of a time tuning out yo-yo the first couple years the car was in the US because of just this coupling. (There were many an ECU updates coming out at that time... Some good, some not so good.) Things seemed to settle down in about 05 or so, occational reports of yo-yo kept showing up, just with much, much less frequency.

Anyway, the stiffer spring of the DT valve changes both the frequency of the oscillation, as well as the vacuum point where the issue can come up. If it moves the problem spot off of a bad part of the tune (bad being defined as a place that can lead to oscillation), the yo-yo goes away. But there are also cases where it has moved the problem spot onto a place in the tune with issues, and has induced oscillation. Those that run into that where it isn't fixed by checking the install tend to just sell the vavle in the marketplace as they move fast and move on. But it can and does happen.

The VGS mod is more interesting from a stability point of view. On the transition from open to closed, the vacuum pick up is moved to a location where closing the valve leads to increased boost, closing it further. This type of posative feedback tends to really kill oscillations. As it opens, the same type of posative feedback will occure.

The VGS mod is more directly coupled to oscillatory supression, but doesn't really do that much to engine control and driving feel. The DT valve isn't directly targeted at yo-yo (even though it's roots are from working on that issue), but does have a very large effect on how the car behaves, with the SC boost coming on earlier and more abruptly. I'd guess that now Chad sells the valve to customers more for how it changes the driving feel than for yo-yo problems.

Matt

 

the problem could be that you live in georgia. i think if you move to massachusetts, the problem would be resolved.

:beer

 

Only issue with Massachusetts is the silly accent. Well, that and those winters... Y'all can have that white stuff. We like to drive too much to have to worry about snow.

:wink2

 

You've never driven until you're going sideways in the white stuff on a mountain road. You want to learn car control? Ok, we'll just hide the road and make your tires virtually useless. That'll teach ya some car control.

 

So...... Jeffster06, did you try to re-set the ECU, and did you notice any difference with the yo-yo afterwards?

 

TB codes...

Are not that uncommon. Before you spend on a TB, undo the electrical connector, use some really good contact cleaner, and make sure that the. Connector is really well seated.

Matt

 

i still think that moving back to massachusetts would solve the problem! i miss my drinking buddy! who knows when you'll be back up here and if i'll ever get the chance to head down there! just remember who gave you that final push to buy your MINI! i think this is your car's way of saying "move back jeff"

:deadhorse:

 

Let's see now.......

Vinegar pork BBQ ........

Lobster dripping in butter.......


I'd be chasing the lobster

 

Wait till November - you'll still be enjoying late summer while your friends up north will be seeing early snow. I moved from Boston to NC five years ago.