1994 SL bucking when starting

Hi whenever the car has been sitting for a while, it starts fine but after a couple of minutes it starts bucking sporadically between 30-40 mph and gets better after driving it for 15-20 minutes. It is particularly bad if car has been parked at an angle, or if it is rainy or particularly muggy. Wires? fuel filter? anyone have any idea? If it is the fuel filter, do you know where you can the plastic tool for replacing it, as mine did not come with it??

Replace the ECTS with the 2-wire connector with a brass one from the auto store.

Clean your throttle body and EGR.

The filter does not need a specific tool to get replaced.