I have a 1993 Buick Century that will stall in transit, not start when shut off for a few minutes. New alternator,fuel filter, tune up, 200,000 miles, need someone to direct me.
Is your ‘Check Engine’ light on? If it is have the PCM scanned for diagnostic codes and post back.
Also indicate whether this engine is the I4 or V6 and the liter size.
If the CEL is not on, the problem will probably be in the ignition system. Carry a spare spark plug. When the engine will not start, remove one spark plug wire; insert the spare spark plug; rest it on a metal part; crank the engine; and look for a white/blue spark. If there is no spark, you will have the spark system diagnosed to determine if the Crank Position Sensor and Cam Position sensor are working; the igniter is working; and if the ignition coil(s) are okey. This is probably going to be a heat related problem and will be difficult to diagnose unless the mechanic has the problem occur under his/her watch.
Hope we can help further.