Quote Originally Posted by idrivejunk View Post
Sounds like injector wiring (or injectors, maybe swap those around, too?) is the only thing left
So I did swap injectors 3 & 5. No change. I believe it would be worth checking resistance on the signal wires for injectors 3 & 6. I just need to dig up a wiring diagram.

except of course grounds which I assume you verified, along with firing order.
I mean, I did a visual inspection and everything looks good. Didn't see any obvious missing grounds or chaffed wires. I triple checked that the plug wires are in the right spots. Even printed out a cheat sheet. Maybe I'll swap 3 & 6 just for grins.

I don't know that cranking pressure would tell you anything unless there's stuck valves.
Or broken valve springs? Then again, zero misfires at idle...

What did the plugs from those holes say?
Great question! Those plugs looked exactly like the other 4. Kind of like a toasted marshmallow. Light brown. No crust. No soot.

I would think comparison to healthy fuel trims might offer a hint.
Agreed. I haven't let it run long enough to go into closed loop.

Connecting an analog (plain old regular) vacuum gauge would point out a manifold or valve problem.
Worth a shot I suppose. So strange that it only misfires on 3 & 6 though.

I do know I am not fit to advise but one reply beats none.
Nope, I appreciate the feedback. Gets me thinking in multiple directions.