kabz

So things have moved on a bit with my 88 NA GXL.
Car was running great apart from not being able to rev past 3800 or so except at idle.
I thought this might be a fueling issue, so I bought a new pump, fitted it, and whilst testing, accidentally grounded to the BW wire at the test connector, instead of the T of the yellow connector. This promptly blew the EGI COMP 30 fuse, which I replaced with the RETRACT 30A fuse.
Since then the car has run progressively worse. It started immediately after this, but after about 1/2 mile it was stuttering, running on one, trying to die. I made it home, but just barely made it up the driveway.
Now it's starting but only fueling the rear rotor.
I've tried the following:

• Changed plugs - front plug shows no sign of fuel/combustion, rear plug looks decent, couple of dark threads, usual carbon
• Refitted Walbro GSS342 fuel pump - genuine, has the metal internals
• Removed UIM, tested with key on, turn cas by hand, good spark, BOTH primary injectors click happily
• Used my fluke to look at inj duty cycle whilst cranking - non-zero on rear LG/R, nothing doing on front LG
• Checked power at BY to injectors - 12v at key on and continuity between injectors
• Compression tested, high-90s/low 100's on both rotors, warm engine
• Tried an alternate ECU. No change.
• Changed injectors. Runs on rear inj only. Needs some ether to get started as they are in theory 550 but seem bigger.
• Checked LG/R and LG from ECU connector to injector connector - both ok
• Regrounded ECU grounds to stud at lower left of ECU

One ongoing issue is that not all the warning lights come on at key on, before cranking, only the body ones light, hatch, washer, doors etc. This seems like it starts happening when the battery drops to 12.3v. Seems ok above that.
tl:dr front injector clicks when testing, but doesn't work when running.

kabz

Made some progress. I tried the car earlier and it ran on one injector, but the front one this time.
So I've been read through every single Rx-7 injector / electrical troubleshooting thread, and I decided to try checking the voltage at the green wires with key on.
LG/B was good, but LG was 1.5v not 12.65 as expected.
Partial failure is good as it points to high resistance somewhere. I already pulled the main relay to see if it was carboned up or something.
Anyway, looks like when I shorted B/Y to ground, it may have burnt the injector wires.
Quick video:

kabz

Further update. Problem was still there after replacing a couple sections of the harness.
Problem was still there after splicing entirely independent wires from the ecu to the injectors.

New injector connectors have been ordered.