1990 500sl Hard to start when cold

[bas_500sl]

Hello everyone. My name is Bas. Wanted to say hi! Just bought my 500sl about 2 months ago.
I have a 1990 500sl. It takes awhile to start from cold. Will start up no problems when warmed up. Starts to run hot at about 105 degrees plus when in traffic cools off on highway speeds. Also accelerates sluggish when hot. I have replaced all temp sensors, hoses no more vacuum leaks, new fan clutch, aux fans come on. No smoke from exhaust.
Idle is goes up and down. 600-650rpm. could it be fuel related. Spark plugs look good. Seems to run worse when outdoor temperature gets hotter above 80 degrees. What should I look for? Thanks in advance
hard to start
surging idle
runs rough
smell of unburnt gas