cuatrokoop

What is the concensus on removal of said valve? It is a BPV, but has an electrical connector on it. Or, could this just be located elsewhere, such as an actual BPV? I'm having a fitment issue with the CIS system in the CQ, and I can fit the breather line and the vac line to the air box lid (its a factory B3 10v lid, so it has those two ports). However, I am going to have to run a VW Rabbit/Golf air boot to feed the turbo, to get a tight radius that the 5ktq air boot cannot offer (it has to angle down to clear fuel lines, and squeeze between the IM and airbox all at the same time). I've already modified an open element air filter housing I had (it is a Jamex unit for B3 cars) to gain clearance by lowering the airbox and moving it forward and outboard several inches. I can't get any more room, hence the switch.

Here's the clearance I'm working with:
<img src="http://www.audi-quattro.org/cuatrokoop/pics/DSCF0042sm.jpg">

So, can I either totally remove the Decel cut-off valve? Or should I just relocate it and use it as a BPV at the turbo (possibly along with a 2nd BPV from the 1.8t as a safe-guard?).

SteveAngry

I've seen plenty of cars with them missing or unplugged.

Steve
Michigan

birdmanmt

IIRC, it was installed to eliminate fuel spikes during off throttle in gear decel.....this was causing plugs to foul and emmissions issues. i've seen a lot of cars with the port for it on the CIS boost plugged and running just fine.

hth
jeff

cuatrokoop

Well, its not like I won't be running a BPV, I just need to not use it at the air meter plate. No extra port for it...

devil's advocate

Actually just ditch it regardless unless you plan on running a BOV. It is a bypass valve (sort of). The intention was to bypass the fuel metering plate on decel to save gas when the car is essentially driving the engine. (If running a turbo with no decel valve and a blow-off valve you would have serious over-fueling on deceleration due to the BOV. Of course a BOV is not a good situation for any metered air system, but the decel valve makes it almost work) In my opininion/experience ditching the valve makes the cars drive better by eliminating the "surging" feeling as the engine leans out when decelerating in gear. I find most manual transmission cars from the '80s annoying to drive for this reason. In that era everyone was trying to squeeze a little extra fuel economy and fuel injection allowed little advents like deceleration fuel shut-off to gain a fraction of an mpg on the epa city cycle. AAnyway it was still early for the technology and it is very perceptable to the driver and more annoying than it is worth.

5kcstq

I owe my friend one of those. I cracked the nipple on mine and borrowed one from his parts car.

I agree you can ditch it, but I'd like to be the ditch if you do!

I would have used the one from my parts car, but automatics don't have one of those. I guess there's not much throttle plate closing on automatic cars.