As I know people will be curious, here is a report of the work that Chuck at Fuel Injector Specialists did for me. As pictures will tell the tale:
On the left is the before situation.
Spray Pattern: As can be seen, the spray pattern is pretty healthy. If
anything, that #4 injector on the right has a
little impingement that
maybe that is reflected in a forked spray pattern right out of the injector but this resolves into a nice cloud of fuel immediately.
10 Second Static Flow Test at 42.5psi: 78cc of fuel remains across all injectors--performance is consistent.
30 Second 25/75 Duty Cycle Flow Test: Here, performance is variable, with the #1 injector trailing a bit, and #2, #3, and #4 performing pretty evenly (within 5.5% of each other).
On the right is the after situation.
Spray Pattern: Looking good.
10 Second Static Flow Test at 42.5psi: 75cc of fuel remains across all injectors--performance is consistent and 4% more flow compared to before servicing. 450cc/minute, 44.1 lbs/hr.
30 Second 25/75 Duty Cycle Flow Test: Performance is still variable, but the #1 injector is trailing a bit less. #2, #3, and #4 are more consistent (now within 2.8% of each other).
Inductance Testing:
So, here's maybe why that #1 injector is trailing a bit in performance: It is slightly out of spec. These should--per the BGB--test out at 2-4, and that #1 is ever so slightly out of bounds. The others are right at the line but are giving proper service.
Did it stop me from putting them back in? No. I was curious to see whether I had cured the Lorelei's performance issues. But I could probably settle matters to my better satisfaction by sourcing and installing better and more modern parts--perhaps a top feed rail and higher throughput injectors.
As for why this is the case with injectors that have seen less than 50,000 miles? Your guess is as good as mine, but they are 30 years old, and saw some disuse over some years.
In any case, if you want your injectors serviced, Chuck at Fuel Injector Specialists will take care of you and give you the data to make an informed decision about how to proceed.