You need to unplug the spout connector. If you are looking at the dizzy, you will see the big connector with 6? wires on it going to the TFI module. Trace those wires back toward the firewall and you will see the spout connector. This connector should be near the dizzy, and will have two wires going into it. Pull the plug out and you are ready to time your car, remember to plug it back in when you are done.
Mario