M130 Rough running after hot restart

[cadurning]

My 1972 280se M130 2.8 MFI engine is running great. However, after having sat for 30 or more minutes, and still warm, restart is rather rough for a few seconds. Upon a cold start it lights right off and runs smooth. Also an immediate restart, within about 10 minutes she starts fine and runs smooth.

I suspected that fuel was leaking down in the high pressure fuel system. I had the injectors tested. Some leaked and some had a low pop pressure. I replaced all of the injectors with new, still the same problem but the car does run much better. My next thought is that the check valves (ball pressure valves) in the injection pump could be leaking. Are those check valves available? If so from whom?

I am open to any other suggestions.

[280SE Guy]

The check valves are available from Mercedes. When I checked on them back in March they were about $125.00 each. You could always call Gus in CA or Hans in NY for a price.

[cadurning]

UPDATE

It was suggested to me that there might be a "hot soak" or "vapor lock" issue with the fuel system. Apparently MB knew about that problem a the fix was to install a time delay relay and a harness. After checking the price of those 2 parts I elected to heed a different piece of advise. That was to install a momentary switch between the "W" terminal on the TTS and ground. Bu doing that I could give the engine a shot of gas through the Cold Start Sol on a hot restart.

WOW WHAT A DIFFERENCE on hot restarts. Only problem is that the rough running is still an issue tho it's not as pronounced.

I suspect that there is still a problem with the check valves in the inj pump. I have a pump shop that I use for diesel pumps looking into the price & availability of the chack valves.