[rhandwor]

Ohm all the injectors any that are way out of line replace. I've used a small screwdriver with a light bulb in the handle slide the tip along side the wire and check for spark on all cylinders. I've also used an ohm meter and checked the wires it normally runs appx. 1/2 scale.
Take a compression test a bad lifter or valve can cause problems.
Use a can of carb. cleaner and spray along the edges of the intake manifold.
If the engine smooths out you have a leak at this point. Its always possible a gasket is pinched or you have a small crack.
Bad injector wires also cause misfires.