Somehow I posted this in the wrong section before, so here goes again, this time in the right place.

The air pump on an 87 TII is exclusively for smog, right? Reason I'm asking is that I'm searching for an intake leak and I removed it in order to see more of the manifold, so that I can see what I'm spraying. Will running the engine without the air pump, but with the ACV still attached, cause me any grief?

I'm also concerned that the water pump will now only have one belt running it (that being the alternator belt.) Should I be concerned about this? I'll only be idling it.

(Just FYI my problem is that my idle jumps between 1300-1600. No ECU codes.)

 

If you're just running it for a few minutes to check for leaks, then don't worry about it. If you are planning to do this long term, you will probably clog your cats. And as you suspect, one belt will not effectively turn the water pump at high RPM. You need to switch to a dual belt alternator pully.