1992 Toyota Corolla Engines hesitates briefly when cold

I would tune it up, plugs, wires, cap and rotor. If that has been done, then check fuel pressure with mechanical gauge and replace fuel filter and air filter.

The car runs off a set algorithim prior to going into closed loop (O2 sensor reaches 600 degrees and coolant temp reaches 140 or so), after that the ECM controls engine via sensor feedback.

Also check base timing (10 degrees BTDC) with diagnostic port shorted TE1 and B1.