W140 Fuel Pump problem - relay or pump?

[oestek]

My '95 S500 developed an interesting problem... it has done this 3 times in teh past 2 weeks. Start the car, it runs for 4-5 seconds, then dies. After restarting 8-10 times, it runs and everything's OK.

I tried the door lock trick, but no avail. Besides, it does start, then dies.

I can hear the priming pump run - I surmise that's what's getting the car started in the first place. However, because the car runs for only a few seconds, it seems the main pump is not working. I guess it's burning up all the fuel from the initial pressurization.

I've had starter motors develop "dead spots" on the armature where they won't turn in a certain position. Could this be the problem with the fuel pump?

Or is there a relay that may be intermittant?

If so, where would said relay be located so I may test it?

Thanks in advance....

- Kevin