My 450sl has always idled a bit rough but now it stalled completely at a red light. I replaced the plug wires and plugs less than 10,000 miles ago. I adjusted the timing to its correct spec now it runs worse, so bad that I had to advance the timing to get it to idle at all. The distributor cap contacts look pretty worn but no cracks so I ordered a new cap and rotor. Are there any other components to look at that may be causing this such as emmisions components. I've read these engines are notoriously rough idling. Is this all I can expect. Also, before this the car when first sarted took about 3-4 minutes to idle down from ~1400rpms to 750 rpms. Is this normal?

thanks
jmdunn