'85 380SE hard starting when warm
 

In the morning starts fine and runs well. After warm if it sits more than 30 min it takes alot of cranking, 20- 30 seconds. Once cool after a few hours starts fine again. Im thinking it could be a bad fuel check valve. Would this be located by the fuel pump or the injection system? Any other ideas? Thanks!
Dennis

I invested in a CIS fuel pressure tester, its around 80 bucks if you shop around. There are a number of tests you can perform to help pinpoint the problem. Your fuel system needs to maintain pressure for 1/2 hour after shutdown to be within specs. Without knowing for sure you might be replacing parts that are still OK.