where is my car's timing belt located? Need a diagram. on 1991 Mercedes-Benz 190E

Car is not starting, may be the timing belt but need a diagram to locate it.

Asked by for the 1991 Mercedes-Benz 190E
Mercedes has no engine with timing belt .They all have timing chains that last for about 300.000 miles.
If it wont start you have look for something else 'cause chains failure not common on this cars.