Rough idle on this car can be caused by a lot of things. Spark plugs, plug wires, coil/distributor, fuel filter, PCV valve (a $5 part, takes about 30 seconds to change), and even just cracked vacuum lines.
Since you've already done the plugs, start with the vacuum lines (free to check, dirt cheap to replace), then look at the PCV valve, then look at the plug wires (if you haven't already). After that, it probably wouldn't hurt to take the distributor cap off and look at the rotor and contacts around the cap (clean them off if they have any white looking corrosion).
-How to find vacuum leaks- https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge
Let us know what you find.
Thursday, June 22nd, 2017 AT 7:23 PM