trouble starting in '86 5kcstq (HELP! More problems!!!)

[Pat Dooley]

> You mean like the one we have in our 5ktq cars?  The digital full range
> vacuum and boost gauge that taps into the intake manifold?

Yes.  Just like that one.  I worded that statement accordingly because I
just got my 5kt back from a friend.
Didn't feel like taking it around the block to check the range of the gauge.
>
> > A free-wheeling compressor wheel will have no effect on the
> air-flow plate
> > compared to the motor's natural vacuum.
> >
> > You would only be rich under boost.  Metered air would blow out of the
> leak
> > source instead of burning in the combustion chambers.
>
> How do you reconcile metered air blowing out the leak with a lean
> condition?

Re-read the post.  I said it will only be rich under boost.

> If the air has been metered, the ECU will add gas for that air.
> If the air
> then leaks, there is still the gas in the system.  That makes rich in my
> book.

I'm reading the same book, at least that chapter.

>
> > ~90 percent of the time the entire intake tract will be in
> vacuum, meaning
> a
> > lean condition, upstream or downstream from the compressor wheel.
>
> There is a vacuum only after the throttle body, in the intake
> manifold.  The
> rest of the system is always under pressure.  I believe you
> forgot to factor
> the throttle body into your hypothesis of how the system works.
> That, or my
> hypothesis of how things work is wrong :-)

Need to be specific regarding my factual "hypotheses".  Are we talking boost
conditions or vacuum?
Under vacuum conditions: the ENTIRE intake tract from the air box to the
intake valve is under vacuum.
Upstream and downstream of the compressor wheel are under vacuum.  Prove
it - put a gauge just before and just after the turbo while idling in the
driveway.  It will read vacuum on both sides.
This is what makes the air go into the motor.  No vacuum - no air flow.
BTW, we are using atmospheric pressure as our reference.
The vacuum is greater after the throttle plate, lesser before it.

Under boost: from airbox to compressor inlet in under vacuum.  This section
is never pressurized.  From compressor discharge to intake valve is
pressurized.  The throttle plate controls the air flow, has nothing to do
with vacuum.
>
> >
> > If you don't believe me, rip a hole in the Michelin man
> hose(after turbo)
> > and hook up an air/fuel meter.
> > Guarantee it will read lean if it idles at all.
>
> What are the terms of your guarantee? :-)

Unless my instruments and the basic laws of nature have gone astray, my
guarantee is unconditional.
Regards, PSD.