Re: Timing Jump on 165/TPI System

[Mark Romans <romans@pacbell.net>]

Hey Bruce: If I disconnect my est connector, should I see the advance at
2500 rpm?
I am wondering if this is why I have the idle problem.  Remember how the
signal goes to zero advance?
Mark
-----Original Message-----
From: John T. Martin <gmman@eskimo.com>
To: gmecm@efi332.eng.ohio-state.edu <gmecm@efi332.eng.ohio-state.edu>
Date: Sunday, January 09, 2000 10:33 AM
Subject: Re: Timing Jump on 165/TPI System


>My  $.02
>
>That is a normal condition, also a test for P/U coil signal strength. The
>advance is triggered by the P/U coil signal amplitude, not RPM. It is a
back
>up as I understand it, but a good test if you suspect a weak magnet in the
>dist. We had a run of K engines with shaft problems a while back and in
>bypass (est disconnected), 2500 rpm the advance was not triggered. Also the
>weak pick-up signal affects idle quality.
>-----Original Message-----
>From: Craig Moates <craig.moates@home.com>
>To: gmecm@efi332.eng.ohio-state.edu <gmecm@efi332.eng.ohio-state.edu>
>Date: Saturday, January 08, 2000 9:08 PM
>Subject: Timing Jump on 165/TPI System
>
>
>Folks,
>
>A question:
>
>With timing control connector disconnected (ie. setting timing on a
>165-based TPI motor), timing should sit still, which it does for me at low
>RPM. However, when I idle it on up to say 2000 or 2500, it seems to advance
>like 12 degrees or so, instantaneously, and hold up there until I idle it
>back down. Then it jump-returns to the previous value. This is all
>timing-light based. Any thoughts on what is being seen? There's about a 1-3
>degree drift on idle-up, probably from timing chain stretch, but that's not
>huge.
>
>Anyways, fishing for thoughts. It's not problematic, just would like to
>understand what's happening and why.
>
>Sincerely,
>Craig
>
>
>