loud Bosch fuel pump in 86 Spider Quad?

[Brad Karp <bkarp@domain.elided>]

I drive a 1986 Spider Quadrifoglio, about 188000 miles on it (with a full
engine rebuild and new head at 172000 miles).

Two years ago, when it failed to start, the shop I then used replaced the main
fuel pump, and the car ran well again.

About six months ago, my new shop (Roger's Autoworks in Oakland, CA) noticed
while doing other work that my in-tank fuel pump wasn't operating. They
replaced it. I had them replace the fuel filter for good measure, as I never
have replaced it, and have no idea when the previous owner might have.

Three days ago, as I accelerated uphill, the car stalled and wouldn't restart.

Roger discovered that the fuel pump fuse next to the ECU had melted the
fuse holder (which I'm told by all is a common occurrence on these cars).
He removed the bayonet-style fuse holder and replaced it with a more recent-
style "twin-blade" fuse and fuse holder.

Once he replaced the fuse, the car ran again. I drove home, stopping once for
gas and once for an errand. About 30 minutes later, when I went to start the
car, it turned over strongly, but wouldn't start--fuel delivery problems
again.

I went and bought a new Bosch relay (the larger of the two next to the ECU) for
the fuel delivery system, as I have heard those often blow. Installed it,
and the car would half-start, but not "catch".

Took the car back to Roger's. He found that the main fuel pump is
inoperative; draws 15 amps but doesn't run. Keep in mind that the dead pump
is only 2 years old, used for fewer than 18K miles. He replaced it with a new
Bosch pump.

Now the car runs again, as of yesterday afternoon. But the fuel pump is
quite loud. If I am idling, I can hear the pump whining, and the whine fades
in and out--it is not a continuous sound. I don't remember it being this
loud previously (though I did hear it regularly before).

I'm concerned that the pump isn't the root problem; that there's something
else wrong that will cause me to fry this pump, too (and perhaps more fuses
and relays...)

Questions:

	1) Should the fuel pump make a droning whine that fades in and out?
	   Again, this is loud enough to be quite conspicuous in the car's
	   interior. Or is that definitely normal operation?

	2) If the whine isn't normal, where should I look for a cause? Crud
	   clogging the pump from either my fuel lines or gas tank? Is this
	   a commonly seen occurrence?

All assistance greatly appreciated! I don't want to kill another $215 Bosch
fuel pump...

Thanks,
-Brad, bkarp@domain.elided
86 Spider Quadrifoglio, daily driver
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