747 Timing Connector and misc questions

Bruce Plecan nacelp at bright.net
Fri Jun 19 14:23:30 GMT 1998


From: Jason Weir <jweir at worldnet.att.net>
Subject: 747 Timing Connector and misc questions


> I was under the assumption that disconnecting the timing connector
>on the GM TBI, took the timing control away from the computer so you could
set the initial timing without the computer getting involved.

At min idle speed, yes.  If you race the engine, you're goofing things
up.  Just set the timing with the at like 600ish rpm.

 I
>am trying to change the timing curve in the chip so to start with I
>graphed the existing curve. I got two similar graphs with and without
>the connector connected? I put the graph up on my webpage.  By the way I
have set the timing at 12 degrees initial advance at the distributor and the
distributor has no vacuum or centrifugal advance.

Have you read the prog 101 stuff?  Does this application use a 1227747 ecm?.
>
>http://home.att.net/~jweir/graph.html
>
>    Is the timing connector just for timing at idle and knock control..
>What am I missing..

At 332 incoming is a couple articles about tuning.  I'd suggest ya
start there, and then the 101 stuff.  Correctly burning chips etc.,
takes some leg work+research to be done correctly.

 Second question is anyone using Needham's PB-10 prom programmer?

Been using it for 4 years, if ya use the mouse for entering data instead of
enter on windoz 95 it locks up.  Just use the enter
button, and it's fine.

I am looking to buy one and that one seems to be what I need not to mention
it is rather cheap. Check it out and let me know what the consensus is..
http://www.needhams.com/pb10.htm
>Jason Weir - 88 YJ - 258 / Howell TBI  145K and counting

Cheers
Bruce




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