924Board.org

[MikeDanger]

just when I think I have it under control...nope.

I have played with the WUR every which way: First here is what was happening, I don't know if they are related.

Things seemed to be ok, I took it for a short drive, Parked, came back a while later, start the car and now its very lean 20+ and barely running. Assuming heat soak.
I have to Enrich the CIS to drive again. I assume its a WUR issue. I get home and with the engine still hot, I swap out another WUR....seems ok at first....take WUR #2 around the neighborhood, seems ok.

Next day I take a little road trip, after the first stop, come back to the car and AGAIN, really lean with WUR #2


What i did: I Took the WUR out of the equation, sort of. The way I think about it, the WUR is simply a LEANING device. I thought, let see what pressure I get WITHOUT the "warm up" parts. So I pulled the bottom off to remove the spring and pressure Pin. So now, its just the In/Out port with no resistance. Getting about 42psi cold with that.

Lets see what happens: Seems Kind of ok. Its not going crazy lean after getting hot. So far so good, so I go on another road trip up to Kenosha Pass, 10,000 ft.

NOW what is happening is that when cruising on the HWY at around 3K rpm, it goes a bit lean around 15-16, NO MATTER THE IDLE SETTING. I set the i'd A/F at 11.8 (down from 13.5) and still get the same near 16. If I give it gas I feel a bit sluggish and maybe even some hesitation.

Now If I floor it and get boost over 10psi, the A/F starts to come down a little towards 14.


My possible thinking is maybe its the BOV/recirc valve??? where some of the boost is getting into the intake between the Turbo and the CIS meter, there by reducing the vacuum behind the CIS plate. and offsetting the fuel supply?
_________________
It was either this or a giant box of legos

[BauerR]

Make sure you dont have any rips in the rubber hose that goes between the turbo and the air meter. You will be chasing your tail with lean issues if you have a hole there
_________________
996 Turbo ('04)
928 S4 auto ('89)
928 S4 manual ('87)
957 Cayenne Turbo ('09)
931 Turbo S2 ('81)
951 Turbo ('87)

[MikeDanger]

I just pressure tested the intake from the top of the Fuel meter back, all good.
_________________
It was either this or a giant box of legos