Several weeks ago my '83 Westy (162K) began running on 3 cylinders until
it warms up a bit.  I thought a fouled plug might be the cause.  I found
one a bit dirty and changed them all only to have the problem persist. 
Seems to run fine after the motor has warmed up.  Won't idle smoothly at
start up, but will afterwards.  Seems to hit on all 4 when revved. 
Problem began after I soldered a broken wire together going to the driver
side rear injector.  Some mechanic had merely twisted it together before.
 At the same time I also replaced the marvelously engineered plastic fuel
distribution tubes that provide gas to the injectors.  They're plastic to
avoid corrosion, right?  They have a metal seal on one end to corrode and
cause replacement even though all else is in fine shape!  Wunderbar!!  At
$27 each it keeps Wofsburg going.

Any suggestions?  Any connection to the injector?  I recently had to have
one of the original injectors replaced.  How can I easily isolate which
cylinder is not firing up at first?

Thanks,

Brian Strange