[rhandwor]

Use a can of carb. cleaner and spray along the intake manifold. If you find a big vacuum leak the engine will smooth out immediately. A pickup going bad in the distributor will cause it feels like the engine shut off and restarted. A module on the side of the distributor can be tested free at Advance or Auto Zone. A leaking EGR valve will cause rough running even stall the vehicle.
Disconnect the vacuum booster and put a bolt in the hose. If the engine smooths out buy a rebuilt vacuum booster. Check the timing an engine out of time will run rough.