1994 s500
 

Clutch fan blew up. Replaced fan, also replaced rad. cap, was weak. Put in new coolant. Car was hard to get started. Ran for about 10-15 minutes. Sounded like it was misfiring, heard thumping/ hammering sound through the exhaust, could not find anything out of place. Turned car off to give it a better look. Still nothing out of place.
Tried to restatrt car and now it beck fires through the throttle body and won't start up again. Anyone have any ideas on what I need to look for now? Thanks in advance for any help anyone can offer. Car has 162773 miles on it.