test pipe Wont make it run rich ...
If you cant figure out whats wrong and your asking us...then LISTEN to what we say you cant accept some advice you like and reject what you dont, these guys know there ****. at least get a stock dv and try it

 

I'm going to play Devil's Advocate here.

Now I know that these cars seem to run smoother with a DV setup, but everyone cries foul against BOVs for rich spiking. Traditional thought (on most turbo cars) is to run a DV instead of a BOV on your car until the DV simply can't flow enough to be effective for a BT setup.

From my understanding, the DV takes relieves the air pressure in the intake just after the turbo so the turbo doesn't stall when the throttle snaps shut. It dumps that air into the airbox.

From there, it must go through the MAF... it has to be remeasured for the ECM to add more fuel.

Why does everyone talk about rich-spiking between shifts with a BOV? A blow off valve is an atmospheric dump and a DV dumps into the airbox. Yes, the DV dumps a change of air into the airbox, but it still is measured by the MAF, which tells the ECM to add more fuel. If the MAF doesn't feel that charge of air, it just wont add fuel for that split second.

Between shifts, the ECM actually cuts fuel (when you remove your foot from the accelerator) so the engine can come back down. Adding fuel would stall the car or keep it's revs up unless it's needed.

So knowing this, what's up? Is there something I'm missing?

 

try recirculating the bov side of the BOV back to itself. that way it'll act like a dv. as for the test pipe problem, you'll need to weld 2 02 sensor bungs on there and then put the sensor in and it should take care of the cel problem but you'll still smell a little bit of gas because you don't have a cat filtering out the crap. i think your problem could be that you're running so rich, you're blowing out the spark

 

Yes your missing the fact that the DV dumps after the maf not in the airbox air is not remesured its assumed to stay in the line which is why when that volume of air is missing it theoreticaly runs rich

Of course having been through the turbo twice that volume is now really hot and probly not good for heat soak problems

 

Thanks, gotcha. I thought the DV hose ran to the airbox. I'll go play tomorrow and see where it runs. It's funny. These are things I never really messed with when I worked for Audi and VeeDub. Things only go wrong with DVs when you start to modify the car or if it's old as dirt, which is not really a common sight with warranty-repair cars. Lots of vacuum leaks, but in 4 years, I never saw a DV issue on an A4!

 

Just found a good diagram of the engine. I see where it runs, thanks for the clarification Slim. Learn something new everyday, despite all my training!

 

Lol no problem. Ive playing with audis for 8 years now I think i learned that in my 5th year