Possibly OT, ??s about a GM feedback Q-jet

[ae2598 at wayne.edu]

The colors are green, white, black, and brown.  Brown is grounded to the
dist. housing.  white passes through to the middle pin of the three on the
side of the module.  As is is right now, the green and black (which go to
the two outer module pins) are jumpered.  I imagine the ECM must
internally close this circuit when it sees no knock signal, and open it
(or possibly it gives a linear response?) when knock is detected.  This
would, at least, explain why we'd jumper those pins to bypass the ECM! As
for the white wire that is presently still connected, is it OK for me to
clip it?  I can't surmise what this wire serves, other than possibly to
give a speed reference signal to the ECM.  The white and either the black
or green (can't remember which offhand) are "piggybacked" into the pickup
coil wires, BTW.

Now as for the carb, I have a non-ECM Qjet that I'm going to throw on for
comparison purposes.  I think the drivability problem we're having is from
excessive richness, and maybe this is just a symptom of a carb in need of
a rebuild.

thanks,
kevin 

> On Thu, 8 Mar 2001 Chipsbyal at aol.com wrote:
> 
> > I'll try to help you here, it's been years since I've fiddled with these. First, you don't have a mixture control solenoid. That solenoid actuates to enlean the accelerator pump shot when the ecm so desires. It can be disconnected with no problems, except a persistant hesitation may finally clear up. The distributor is part of a ESC system. It can be converted to non-esc by disconnecting the four wire connector and jumping two wires on the dist side of the connector. Now here my memory gets a little foggy. If you can tell me the colors of the wires and what position they are in the connector, I can tell you which two to connect. There is a green, black, brown and the last one. The truck won't run with the connector disconnected. I used to get quite a few no starts with this system. The customer always opted for the wire fix over the ecu replacement.
> > AL

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