Starting issue 190E w/m103

On my 1991 190E 2.6 it has a problem, that I would like some help with. If you start it every day, and drive it it's ok. However, if you start it, and go someplace, and leave it set for several days or a week. Then if you come back and try to start it. Well, you can grind it too death and it won't start. It just turns over like there is no fuel or fire & timing to be found. You can do this back and forth for maybe 15 minutes or so, and then you finally may hear kind of a pop of sorts. Then before long it will fire up and run. It will never fail this senario if you leave it parked for several days. Any help on this would be appreciated.

[JimFreeh]

Next time this happens, try cycling the fuel pump numerous times.

If you listen closely, the pump will buzz for a few seconds, then shut off.
Key off, key on, Continue until fuel pressure is restored.

Then, and only then try to start the car. If the car starts right up, or the amount of cranking is significantly reduced, then you are losing fuel pressure when the car sits for an extended period.

These cars have a check valve that is supposed to retain fuel pressure, and they often become weak as the car ages.

Jim

Where is this check valve located? Also, is there not any way to put a scanner on one of these before 1993 Mercedes to pull a code or anything??

[Ferdman]

Rebe, there is a check valve at the fuel pump ... fuel pump check valve.