Tonight I pulled out the computer, and it didn't have any chip in it. I had figured the prior owner would have had a reason to pull the chip and leave it in a bag on the flor (performance chip or somehting), but nope, just an empty socket. God knows why the prior owner would have pulled the chip.
I installed the chip, and I no longer need:
1) the hot to the ornge wire (fuel pump power)
2) The OBD1 debug jumper (A&B).
3) The hose-clamp that increased the idle a little.
With the jumper and engine not running, the computer flashes codes (12,23,34,41,42). For NG cretique and ideas, my interpretation of these by reading Haynes is:
12 - since it goes onto other codes, this just starts the sequence of reading codes. {True?}
23 - MAT low temp indication (where it this one?)
34 - Vacuum sensor or MAP sensor (are these the same or is there a seperate vac sensor - I probably do have vacuum issues)
41 - {not in my book, anybody know what it is?}
42 - EST (Electronic Sparc Timing) - "Electronic spark timing bypass circuit or EST circuit is grounded or open. A malfunction ing HEI module can cause this code" (? is this pointing at the distributor-module?) {The last I checked timing it was about 8 degrees BTC - before I tightened the bolt - guessing it's between 5 & 20 degrees now - will go check as I post}.
And yea I'm still trying to figure out what to do with this truck (keep/sell/junk). Of coarse it's getting closer to something i could sell with a clear concience. And yea the prior owner was dishonest - I wouldn't sell something like what I bought. I guess I bought this from the kind of owner that you guys often imagine me to be - cludge artist, etc - but at least I'm honest about my cludges and wouldn't try to hide them from a buyer.
Ideas and suggestions are appreciated - though please be patient as I do tend to jumper and cludge my own test cases.
Thanks, Elliott
Subject: Isolating the Computer, ESC, and Distrib Module
> Date: Wed, 31 Mar 2004 19:09:12 -0500
> From: snipped-for-privacy@comcast.net
> Newsgroups: alt.trucks.chevy, alt.autos.4x4.chevy-trucks
>
> Anybody know how to isolate the Computer, Electronic Spark
> control, and the Distributor module? The parts-throwing
> approach would be $50 for the ESC, $75 for the computer,
> and whatever Autozoo price for the module. Would like to
> be able to locate test-points for a VOM with known expected
> voltages to test for. It could also have something to
> do with the ignition switch and fuel-pump relay/gnd. I'm
> running out of time for the project and could really use
> the vehicle if it were working. This is on the 87 S-10 with
> a 2.8L V6 TBI. It ran for a few minutes with the motor dropped
> in before the fuel pump pumped all night (probably had a bad FP-relay
> that I have replaced). I think I have all of the wiring hooked up
> but there are a couple wires that look like they haven't been hooked > up for years.
> Thanks in advance,
> Elliott