i have a 91 bird with a 3.1. it has the electrically controlled timing, where you have to pull that connector near the passenger fender to put it in base timing mode to set the timing. well it seems like the last time i pulled the connector to check the timing, when i plugged the connector back together, nothing happenned. i mean usually you can tell a noticable difference in engine speed when you plug it in, and the timing at the mark changes. well i keep trying to plug it in, and it wont change. WTF?!? please help me.

 

Apparently, you have a timing light at your disposal. That will help a lot in the diagnosis.

Disconnect the EST bypass connector (along the firewall as you indicated). Set the base timing at the specified RPM with the light. Note the timing indication. Reconnect the EST bypass wire, and check the timing again. It may or may not have advanced. Whether it has or not, you should have set a DTC while the EST was bypassed. This will set the ECM in Backup Fuel and Spark Mode. If the timing doesn't change after reconnecting the EST bypass connector, shut off the engine, disconnect the battery power to the ECM to clear the DTC, then restart. Check the timing marks again with your light. There should be a significant change in advance.

If clearing the DTC does not re-establish ESC operation, you may have a problem with the detonation sensor input, EST connections, or ECM connections. The ESC on your '91 should be incorporated into the ECM, so there is no separate module to check.