1995 Buick Regal Floods when re-starting after brief stop

'95 Buick Regal Custom - 3.8 liter V6 - When trying to re-start the engine after a stop of say. 10-20 minutes, my car is getting flooded. If the engine doesn't re-start on the first cranking (chugs, sputters and dies) it will not re-start without using starter-fluid. And even then, it chugs and sputters until it finally gets going good. Then. No lasting symptoms. So far I've done a complete tune-up (plugs, wires, fuel filter, injector cleaner, etc.). Any ideas?

Thanks in advance!. Roger :-)