I got my '84 Z31-powered '88 Pathfinder up and running, and it runs like a raped ape except when cold and at idle. If I plug in the TPS (I've tried 4 others), it will idle smoothly but not rev above 2500. If I unplug it, it idles like ass at around 4-500 and sputters and pops and blows clouds of black smoke out the tail pipe but revs freely and responsively when warmed up, as well as the black soot clearing up once it's revved. From my understanding, pins 18 and 25 at the computer are for the TPS sensor, yet the wiring diagram I have labels it as the "throttle valve switch" and only measures idle, mid, and full throttle. The diagram I have only shows two wires coming from the sensor as blue/green and pink/blue, but says nothing about the third wire which is pink/black. Being it's got black on the wire, I assume it's a ground? This is a manual TPS sensor, manual computer, and manual truck. I've even ran the blue/green and pink/blue directly to the computer's pins and it still won't idle, but if I touch those two pins directly together with no sensor involved it'll instantly idle perfectly, just not rev. The Pathfinder TPS sensor has the 3 wires coming from the main body, and a secondary plug coming from the side. According to the diagrams, it's got a throttle valve switch and an actual throttle position sensor with a full-range potentiometer that go to different pins at the TBI computer. I would assume since the Z only has the 3-way switch those other wires shouldn't matter. Again, I've tried 4 different throttle sensors and they all do the same thing. I don't want to drive the truck much because running as rich as it is at idle is horrible for rings and such. Anyone know what specific wires need to be ran to the computer for the Z engine to run right? Any help is really appreciated.
I made a video of it, what hooking pins 18 and 25 directly together does is the same with hooking the TPS sensor up.
http://www.youtube.com/watch?v=BrvAravn6pM
And a video of the truck going, warmed up, wide open (for fun).