High Voltage

I have a 1987 Turbo Tbird with T3/T4 W/FMI The problem I am having is the voltage on the TPS on the Green/Black it won't go lower than 1.4v and on the Red/Black it is 15.7v I drove it it seemed fine for a few minutes then i heard a small backfire the air/gas guage pegged at rich the engine was stuttering and putting out black smoke. I reset the computer it ran for a while then did the same thing.does anyone have any ideas where i can start. the engine was just put back in the car after complete rebuild
Golden Bird

I will say this again..... did you check to see if you have 5.0 +/- .2 V VREF between the orange and black wires???

If you do have the correct VREF, remove the TPS, and measure between green and black with TPS still connected to the harness. Use a screwdriver, etc to engage the tangs on the TPS and rotate it manually to see if the voltage changes linearly as you rotate it.

The Orange and Black voltage is 15.7V when I move the TPS it will adjust up but will not get lower than 1.4V. I need to know how to lowere the VREF and what is probably hooked up wrong that is causing the VREF to be that high
Robert Stevens

Have you run codes???

Sounds like the tps is out of wack, but it also could be the coolant temp sensor.

Good luck,

Travis

this sounds like the switched plug problem I had, and have heard of a few times on here. When I put my head together I hooked the TPS to the connector coming out of the Firewall harness that had the same plug end and similar colors as the proper TPS wire. I tried describing this on 2 different posts but I have no luck with my description. I didn't believe it until I swapped the 2 plugs to the right connectors. They are both the same size and shape connector and within reach of each other Take a look at that and let me know!!
Good Luck!
Mike C

Mike

I forgot about that, I did the same thing this spring when I took off my lower and upper intake. I had them backwards.

Travis

Travis,
You are the first one to acknowledge the existence of that connector, and admit to having them plug in backwards. Over the winter there was a 60-70 post thread with the same black smoke, no idle problem, but I could not convince them of the connector problem.

Mike C

This problem was solved. The Alternator wires were crossed. I now have .9V & 5.1V . I still have the chugging and rough idel. Which side of the firewall are the plugs that can be switched?and are they the black connectors or the gray?