'89 300SEL intermittent fuel pump start issue

[BrettS]

1989 300SEL

I'm having an intermittent problem with power reaching my fuel pump. The problem has only occurred at start-up. When it is going to have one of its episodes, the car starts, dies in about 1 second, then will not fire at all (cranks but no fire).

During an episode, the fuel pump gets no power (checked with multimeter) with the key in either the "run" or the "start" positions.

If I jump power directly to the fuel pump (when this problem is occurring) the car starts and I can disconnect the jumper wire (immediately after starting) without the car dying.

Also, it seems that if I walk away for a while (sometimes just a few minutes will do, sometimes though it takes much longer) and come back, the problem usually has gone away.

Any thoughts on what this might be?

Thanks.
Brett