Aight, my first question is that are you looking at the ECU once you turn the car on? If it flashes once when then key is turned to "ON" and then doesn't flash anymore, you have no current "codes".

Also the "timing jumper" you are looking for has nothing to do with showing the codes. It will however clear any codes from the ECU if jumpered. It is located either above the ECU bundled in the wires above it. *OR* - in the engine bay on the drivers side frame rail near the front of the shock tower.

A useless note is that the 88-89 CRX/Civic's had the timing jumper in the engine bay, the 90-91's had it inside above the ECU.

~Steven