OK, my 90 300SEL suddenly developed a problem, It starts when cold, runs perfect for awhile then stops. Very hard to start after that. I have changed the Overload Protection Relay, It is not plugs,wires or anything like that. (if it was it would work like crap all the time) It is getting fuel pressure, new filter, pump works fine. changed fuel pressure regulator, I am stumped. cold start valve? I just don't know what is up. Any idea's?

__________________
1987 300 TDT
1990 300 SEL