zex,throttle positioning sensor,help
 

i have recently put a zex nitrous kit on my 86 n/a and it does not work for some reason. so i was just checking everything out and in the instructions it tells you to conect the white wire to the voltage output lead on the TPS. so i figured that the wire that has the voltage flowing through it is the one you connect it to. i started my car and had the TPS plugged in, then i unplugged it and nothing changed at all! what does the TPS do? and why wouldnt it have done something to my car when it was unplugged and running. please help.

First thing, the "voltage output" wire on the TPS should be the Green/Red stripe wire on the TPS plug, engine side. Hopefully, that is where you connected the Zex. Note, the connection to the TPS should be intact.

The TPS will not change anything at engine idle, it is preset. However, the ACV was venting air, so your exhaust ports were not getting air injected, making it a dirty engine (again, at idle). At smaller throttle openings (you will notice that the sensor doesn't go much past 1/2 throttle), the TPS is one of the inputs used by the ECU to meter fuel, as well as determine ACV settings for Pollution. This will cause havoc at higher throttle settings if it is unplugged. It will also set a code, which you can read out until you plug it back in, if you have a code readout device. After that the ECU will forgidaboutit. :rolleyes: Hope this helps. :D :cool:

Irv, Keith's dad