Toyota Repair: 91 Camry Hesitation, spark plug wires, vacuum gauge

Question
91 Camry 4 cyl. been having intermitant problems with hesitation. Never happens when the car is cold, usually happens after driving somewhere, car sits for an hour. Starts fine, but then engine idles rough then hesitates when accelerating. Usually does not stall. Problem will usually go away after a couple minutes of driving. Maybe in the EGR system?

Cold Start solenoid was replaced about a year ago, but not the cold start timing switch.  

Answer
It's possible that the egr valve is staying on at an idle causing this condition, the correct way to check the system is with a vacuum pump and a vacuum gauge.
It is more common for the engine to have a misfire so I would recommend doing a tune up which includes replacing the spark plugs, the spark plug wires, distributor cap and rotor.