I have an 86 IROC and there is no catalytic conv. on the exhaust. Does the computer retard ignition timing. I have set the baseline timing at 6* by jumping terminals A and B. I checked it again after pulling the jumper wire and unplugging the batt. for 2 min and my timing was at 4* at an idle. The check engine light is on and it flashes code 32 (EGR)

 

You have done something but not really set timing. There is a brown wire that is connected in the middle by a weatherproof plug that is by the pass shock tower. You disconnect that and use a timing light then you reconnect it and the timing is set.

 

I have a brown and black wire that runs from the pass side over the heater box. Do I disconnect it with the motor running? Do I still need to jump terminals A and B?

 

It is a tan or brown colored wire with a black stripe. It comes out of the harness and has a weatherpack connector in it. You disconnect it at the connector and that stops the ECM from altering the timing electronically. At this point, you use your timing light to get the base timing. Nothing else.