RE: Injectors
I had a recent experience with injectors that may e of interest.  Since the
injectors in my '90 WBX were original I acquired a set of used injectors,
had them rebuilt and installed.  One failed (probably stuck open) at about
120 miles.  Replaced with a used injector and I continued on with a month
long 3,000 mile trip with no further incident.
But, running three newly rebuilt injectors the Westy ran better than it has
in some time.  No major difference, just a subtle 'it's better' feeling in
all driving conditions.
Moral of the story:  Maybe, "Don't fix it it ain't broken" and at least know
that although the injectors rarely fail, they can when messed with.