I have newer ignition parts (plugs, wires, distributor and cap), but was having rough idle problems. Noted small intake leak and cracked intake flexible hose (electrical tape was not a good fix). I cleaned the throttle body then ran to see significant improvement in idle and performance (smooth and faster accel). Then replaced flexible hose and idled even better but still not all the way there. Then replace the intake manifold gasket and was the final thing to make it idle smooth and steady.

If you have a high milage car (230,000 on mine) that does not idle smooth, check out these items and fix them. It's well worth it. It's like a new car again.