5ktq and Boost loss (after MC rebuild/upgrade & T3/K26 turbo) - it was bypass valve!

[Ken]

Regarding the vacuum source for the bypass valve:

Here's some quotes from SJM's site:

http://www.sjmautotechnik.com/turbo.html#bypass

"On the 10V Turbo engines in the 1986-90 5000TQ/200TQ when connecting a hose to the Bypass Valve small fitting:

DO NOT USE THE SMALL VACUUM PORT ON THE INTAKE MANIFOLD NEAR/BELOW THE THROTTLE VALVE TO GET INTAKE MANIFOLD VACUUM/BOOST.

THIS FITTING HAS PORTED VACUUM THAT CHANGES WITH THROTTLE OPENING AND WON'T WORK.

DO NOT USE THE SMALL FITTING AT THE IDLE STABILIZER VALVE HOSE CONNECTION EITHER, AS THIS CONNECTION GOES IN FRONT OF THE THROTTLE VALVE, AND DOES NOT HAVE INTAKE MANIFOLD VACUUM."

I was actually thinking about how this may affect my SchrapnelKnobben mod, since I think I may be using the ISV port for the source of my upper WG pressure.  My WG might be doing weird or non-optimal stuff when I shift, I don't know!  Any comments here would be welcome.

Later,

Ken

Quoting Ben Swann <bswann at worldnet.att.net>:

> Allright!  Ken wins the lucky cigar!  It was the bypass valve.
>
> I overlooked this completely before since it is/was brand-new.  I
> thought it would at least get me through testing things out.  It seems
> to pass gas at around 1.5 bar which is why I was not obtaining more than
> that without really pushing it.
>
> It blew out the cork when I hit the 1.8 bar cutout and shifted.  Now it
>
> acts more like a blowoff valve, since with the cork out you can hear it
>
> start hissing when 1.6 bar is reached.  Ok, I put the cork back infor
> now until I get a proper one.