Thanks to sams91se from clubgp.com, we’ve determined that the mystery pipe is actually for a vestigial smog pump specific to 1991-1993 manual-transmission cars that is no longer needed with the newer 1995 engine. Sweet!
So with the last vacuum line connected up, the main exhaust pipe bolted back in place, all the heater core pipes accounted for and all the radiator hose clamps tightened, it’s time to crank this thing over. And….
Click.
Huh. Try the 50 amp battery booster.
Click.
The engine better not be seized!! I’ve turned it over by hand during the rebuild, I know it moves. Out came the breaker bar to turn it over. It was a little stuck at first, but it turned.
So I know the starter worked before I pulled the engine out, and it had been replaced just before I bought the car. So it shouldn’t be screwed up just from sitting in a garage for two years. Oh wait, I only put…
… One shim in it. Another trip to the auto parts store for starter shims. The starter is probably hitting the flywheel from being too close to it. A couple shims oughta move it out and it’ll start normally.