My 89 300E starts on the first try and runs smooth when the engine is cold. Once it is warmed up, restarting is rough. It never restarts on the first try. . .it'll start, stumble, and quit. On the second try, it will start and idle very rough for the first minute or two. Gradually it smooths out and everything is fine.

Any thoughts?

FYI, I've recently replaced the fuel filter, dist cap and rotor, and plugs. I have a new set of wires on their way as well. I also ran a can of Techron through the fuel sytem and changed the oil a couple of weeks later. The car now idles smooth as glass and runs great. But I cannot seem to cure the warm restart roughness.

Thanks for your help.