the second issue I am experiencing is the engine idle keeps fluctuating on 1994 Mercedes-Benz C280

the idle fluctuates up and down and some times it will be steady but mostly it keeps fluctuating,any advise would be appreciated ,what are the possible causes.

Asked by for the 1994 Mercedes-Benz C280
poss dirty throttle body. have throttle body cleaned and see if that helps to start with