RE: TPI '165 pulling timing after Cold start

["Marteney, Steven J." <smarteney@xlvision.com>]

Knock sensor has a certain impedance the ECM can detect (4.7kohm?).  When
not connected, it won't find that and should set a code.  Does the ECM
remove timing if the knock sensor isn't detected?  I would think it would,
but have no knowledge.

What are you doing to adjust cold-start?  My 89 165-based (soon to be
730!!!!!) 350 TPI has a terrible time starting when cold.  Acts like not
enough fuel.  I have played with the PW correction vs. battery voltage in
Tunercat and can make it much worse on hot and cold starts by lessening the
PW.  Increasing the PW (so far) has had little effect.  Doesn't seem like an
air problem either.  Doesn't matter whether my foot's on or off the gas.

Anyone know if the 165 ECM controls the 2 second fuel pump enable when no
oil pressure is present?  where that may be in the code?

Steve (pulling 730 this weekend 8^)  <-- note: grin bigger than Texas)

-----Original Message-----
From: Gabe [mailto:gellett@earthlink.net]
Sent: Thursday, July 20, 2000 1:42 PM
To: gmecm@diy-efi.org
Subject: Re: TPI '165 pulling timing after Cold start


Will it set a code with just the knock sensor itself disconnected?  I
thought
the sensor inputted a frequency into the ESC which then conditioned it and
fed
it into the ECM.  I figured the lack of those frequencies would just be
interpreted as a lack of knock.

The ESC module and all associated wiring are intack.  My theory was (keeping
in
mind that I could not burn new calibrations at that time):  It was losing
power
between shifts, I wanted to see if the ECM was taking away advance between
shifts, it was.  I thought the disconnected knock sensor would be just like
a
knock free engine to the ECM.  Last night I burnt a couple new chips and
tried
them out, didn't think to reconnect the knock sensor.  Was trying to correct
cold start (one thing at a time).....

Thanks
Gabe

Bruce Plecan wrote:

> Before even trying to diagnose the system you should have it close to
right.
> Unless you have the flag disabled for the ESC test you need to figure out
> why it's not setting a code.
> Grumpy
>
> > Why does my '165 seem to pull about 15~20 deg of timing out after cold
> start and
> > leave it out until I am running up the road a ways?  I have tried a few
> > different stock calibrations, namely ARAP, APYP, and APYN - I believe
all
> those
> > are '89 code.
> >
> > BTW, can anyone tell me the application for APYN - I have been looking
for
> a
> > downloadable '89 305 auto, code to start with (I just got my EPROM
eraser,
> so
> > let the games begin!)
> >
> > Anyway....  This removal of timing causes some nasty derivability
problems
> when
> > cold (as well as a nasty exhaust rasp) and I can't seem to get rid of
it.
> I
> > haven't figured out the exact event that is causing the timing to go
back
> in
> > when it does (maybe CL?), for obvious reasons, this event is hard to
> catch.
> >
> > Right now I have the knock sensor disconnected, and the ECM is setting
no
> codes
> > of any kind.
> >
> > Thanks
> > Gabe
> >
> >
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