decel valve same as bypass valve?

[Bernard Littau]

> >Is the MC airbox deceleration valve the same part as is used for a
> >bypass valve in the turbo applications?
>
> Decel valve on CIS cars is for shutting off the fuel when you're
> decelerating; the bypass valve is for helping keep the turbo spin by
> opening a path for air any time manifold vacuum is dramatically less
> than pressure at the turbo.
>
> Far as I know, they are completely different.

The valves looked to be the same, or very close to the same, upon visual
inspection while the decel valve was still installed.  It's tough to see in
there even with the fender liner removed.

FYI, the decel valve shuts down the fuel by allowing air to bypass the
metering plate on the CIS head -- the decel valve controls air flow just
like the bypass valve on the turbo bypass installs.

Best,

Bernard Littau
Woodinville, WA