A few newbie questions...

[Rex Weatherford]

----- Original Message -----
From: "Bruce Plecan" <nacelp at bright.net>
To: <gmecm at diy-efi.org>
Sent: Wednesday, October 25, 2000 3:17 PM
Subject: Re: A few newbie questions...


>
> You'll only hear it when you exceed the amount of retard the chip allows,
if
> you hear it pining, get out of it!.

I don't think that will happen, but I'll keep an ear out..

>
> >The O2 levels
> > looked OK (.876-.920) but that is with a Bosch sensor from Pep Boys..
The
> > disturbing part was the amount of KR being dialed in!
>
> The O2 dialed in KR?.
>

I didn't mean that.  Sorry if it came out that way.  I meant that it was
disturbing me as to why the ECM was dialing in that much.  Doesn't seem
normal, but I'm very new to this.


> >It goes from 3-20
> > degrees.  It varies from 17-20 degrees at 5000-6900 RPM.  When this
> happens
> > my total advance drops to 12-16 degrees.
>
> Just like it should.
>

Ok.  Do you think that little advance is normal?  (I realize you probably
have no reference with this engine)


>  My calculated duty cycle at these RPMs is 70-90%.
> > So is the Bosch sensor incorrect, or does it not really matter what it
> says?
>
> In general ignore it..
>

Will do.

> I tried changing the
> > knock
> > sensor and that didn't help either.  Perhaps this is some mechanical
> > noise?
>
> Always that chance.
>

I guess anything is possible with 115,000 miles...


> > Does viewing a dyno run help anyone with this?
>
> Maybe for finding an exhuast rattle.
>

I have checked all heat shields (there are none under the car now) and
looked for ANY type of contact.  So far none.  I even took extra measure and
bent anything even close back with a hammer.

I DO have a video of a run though, and some graphs..   <digging around..>

Here they are:

http://www.beretta.net/fast_lane/dyno_charts/gtz/5_18_00_dyno_runs.jpg

The shakey line from 5000 RPM up has been there since I started with this
car over a year ago, so I assume it has been having this high RPM knock
since I purchased the car.  Run #1 isn't on here, but it has the same
roughness.

Here is run #1 and run #6.

http://www.beretta.net/fast_lane/dyno_charts/gtz/rex_run1_vs_run6.gif

Here is a video of one of the runs...   Notice the resonance that shakes the
camera??

http://www.beretta.net/fast_lane/movies/dyno/5_18_00_dyno.rm

This directory has all the data I have on the knock problem..

http://www.beretta.net/fast_lane/dyno_charts/gtz/knock_data/

>
> I'd lighten up on the racing till you find out where and what to change,
and
> rather risk blowing it up learning start with the low chance of china
> syndroming the engine areas.
> Bruce

So I guess that means cruise and idle values.  ;^)

Thanks again.  If anyone has any more input I'm all ears...  My CSH is ready
for reading tonight....  Gotta go get a fuel filter.

What is the file extension for diacom files?  Is it DBF or G??.  I can't
remember and I can't find any of them...

Rex


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