Ive passed the info along. THanks.

Regarding the CEL... They tried to code it (jumping the under-dash wire)... and the cel light won't blink.
Is there a different way to code obd0 cars... or more specifically obd1 converted obd0 cars.

Also, the chassi is original SI

 

88-89 has the "check timing" connector on the driver's fender slightly forward of the shock tower, most OBD0-1 harnesses are pinned to that.

90-91 has a "check timing" connector in the familiar OBD1/2 location.