Today I bought some Bosch +2 Irridium plugs and put them in the 300E. Couldn't get any Non-Resistor Copper Plugs anywhere. Car idled much better and took off with more power. Still have to crank to start though. We'll see if the idle lasts. Was 106 degrees outside today. Before it was stalling and now it isn't. I need to adjust my Lambda for optimal mixture but not sure how to do with laymen's tools. Anyone have a link they can post for me? BTW, old plugs had carbon deposits around the base of the threads. Am I running too rich?