Got my '87 TII running again last night, or rather got it running better than before. Found it had 3 trailing plugs installed, and the leading and trailing coils run to the wrong plugs So I bought one more leading plug and wired it up right, cleaned my battery terminals and fixed the alternator wire terminal (at least temporarily). Cranked it up, sounds good... except that it's revving to the sky by itself, w/ no throttle applied So I guess either something has the throttle hung a little, or a vacuum leak.

Anyway, I have a couple questions:

On the S4 TII, the TPS sensor is kinda like a push button, right? Is it supposed to stop moving before the throttle is wide open? It looks to me like it only works for about half the throttle travel, unless I have the wrong TPS. Also, when my throttle is fully closed when cold, it barely even pushes the tps button. I know the cold start system holds the throttle open a little til it warms up, but how much?

If my throttle is hung up somehow, it may explain it, but I've had this car running before, even though the wires were mixed up it run okay but hunted at idle. I let it run for 30 mins, the needle got up to 1/4 gauge on the temp and the throttle/cold start/ tps position at idle never changed. So I'm kinda unsure about where the throttle/tps position should be at idle, I'm pretty new to rotaries and this car was worked on by idiots before I got it.

 

100% Normal in all accounts.
The TPS is only active for around 1/4 of the throttle range.

TII's are common to have sticky throttle cables... they are routed above the turbo, and the resultant heat causes them to break down and crack and become sticky.
With the car is fully warmed up, the TPS should be partially depressed. What you described is normal.
I would try resetting the idle speed via the FSM specs, making sure to reset the TPS afterward.

 

Well, I found the throttle problem -- squirrel nuts lol. So little critter apparently was eating nuts up there and dropped the shells down in the linkage and jammed it open. I removed the UIM and TB together and cleaned everything out and replaced it.

However, I tried setting the tps afterwards, tried to set it to 1k ohms, got as close as possible, which was like 1060 ohms. Still hunted at idle, so I set it to 1 volt. Same thing, still hunts. However it does it under throttle too, like if I hold it at 3k, after a few secs it will start surging. Could I have an AFM problem? I checked all the intake hoses, they're good.

BTW, out of curiousity, what does the computer go by once it's not getting anymore TPS signal? AFM?