Hey I have a S5 T2 and I have no previous experience with the PFC. I have managed to add enough fuel to the table to get the motor to run but its idle is a bit erratic and I wanted to try and smooth it out. I purchased a BAC valve since it was blocked off and slapped it on only to have it rev up to 3k RPMs and hold there. I found out by putting my hand over the open nipple that it was ingesting large amounts of air and blocking it off made it idle down normally.

Now, my issue is since this is not using the stock AFM, there is no way to "meter" the air. Is there a setting I need to change in the PFC to tell it to use an idle valve that I'm missing?

 

did you find a fix for this? I would think the air inlet to the bac valve needs to be routed to the pre throttle plate side of the intake system??

 

On a T2 you can just put a breather filter on the BAC valve.

OP needs to check for vacuum leaks, it sounds like his gasket didn't seal.

 

The way he describes it, putting his hand over the bac valve and it idles down. His bac valve was the vacuum leak. arghx is there a way to control the functionality of the valve thru the pfc? I've done this exact thing with a pfc equipped TII and it doesn't want to idle down unless I unplug the bac valve from the wire harness. Maybe wired into the datalogit as an input? I haven't really dug into it too much on the pfc side of things, just wondering..

 

Reset the PFC , then reload the map, allow the PFC to learn the BAC.

 

Thanks! I'll give it try.

 

Ditto. One of the most annoying parts of a PFC.