1987 Pontiac Fiero timing

Here is what the factory service manual says

OE does not publish a timing procedure for this vehicle. The timing is set by following the procedures on the Vehicle Emission Control Information label located in the engine compartment.

The spec is 10 degrees

Most vehicles have to be put into manual timing before setting base timing. On most GM OBD1 cars this can be done by jumping terminals A and B of the data link terminal.