10 vT EM? NOW G-tech Pro

[Jim Green]

--- Marc Swanson <mswanson at mswanson.com> wrote:
> > my car
> > doesn't run as bad as if the knock sensor is
> unbolted
> > or simply unplugged, but somewhere in between.
>
> I think you may need to take a close look at your
> fuel maps.

Nah, the fuel maps are good, but this is making it
hard to keep them consistent since the mixture changes
a little based on how much the timing is advanced.
Believe me I've bugged Javad enough about this because
I thought it was fuel system related, but after
troubleshooting that to the max, and fixing a few
issues with the placement of the dual injectors, I've
been able to really narrow it down to ignition.

> You shouldn't
> need the knock sensor as a tuning device, rather a
> safety net.  If you car
> runs badly with the knock sensor unplugged (unless
> the ECU senses this and
> backs things way off which I don't think is the
> case), you may be running
> lean.

That's exactly what happens, if you unplug it or
unscrew it and go for a drive around the block you
will have a check engine light that goes crazy, and
hardly any power.  But who knows, my car isn't exactly
normal.  My impession was that the ignition starts
with the premium fuel map then retards ignition a
little if knock is sensed, then if it keep knocking it
will switch to the normal fuel map and then keep
retarding even more if it is still knocking.  So it
has to have it hooked up since it is kinda pushing the
advance as far as it can go from startup, then
figuring out where it needs to be from there.  Also
simply by unscrewing the knock sensor and leaving it
hanging, it will go to full retard, so that tells me
it may still be trying to get more advance, but since
it isn't sensing knock it goes to full retard.  Or
it's just smart and since it doesn't "hear" anything
it goes to full retard.  I've been thinking about this
WAY to much!

> Then again I'm sure you've got an o2 meter
> hooked up so maybe the ECU
> does back things off when the knock circuit is open.

Yep, my lifeline.
http://www.geocities.com/jeg1976/Gauges-f.jpg

I'll let you know how it goes tomorrow.

=====
Jim Green
'89 90tq EFI
http://www.geocities.com/jeg1976/car_home.html

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