Grab a can of aerosol carb cleaner. NOT brake cleaner!
Take the lid off the air cleaner. Allow the engine to idle, so it's running rough...toss a 1/2-second spritz of carb spray into the primary venturis.
IF (big IF) the idle perks up, start looking for reasons that the air/fuel mix is too lean.
Remember, half of all distributor problems are found in the carburetor.
