528e - Won't start, won't run

[Stas Lotyczewski <slotyczewski@xxxxxxxxxxxxxxxxxxxxxx>]

I'm hoping someone can offer some diagnostic insights 
pertaining to my son's 1986 528e.  A couple nights ago, 
at a stop light, the engine shuddered and quit a few 
moments later.  He had it towed to a nearby friend's 
house, and the next morning we (a) replaced the fuel 
filter, (b) cleaned up all six oil-fouled plugs, and 
(c) duct-taped a cracked vacuum hose we discovered, 
but to no avail.  When it would start, after much 
cranking, the exhaust was quite dark, and it would 
run only with much throttle feathering.  The fuel pump 
appears to be working (I can feel a vibration when I touch 
it as the car is cranking).  After a minute, it stalled 
and wouldn't even "catch".  The car was towed to a nearby 
garage (but about an hour away from home, yuck), where it 
presently sits.  If these symptoms sound familiar to anyone, 
I'd appreciate hearing about some possibile causes.

Thanks in advance.
Stas Lotyczewski
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