R34 GTT TPS Voltage issue

[Kuhaku]

Hi All,

Having a TPS issue on my R34, have a R34 GTT TPS on a R33 TB for the front facing plenum now checking wire from ECU and plug I am seeing 5vs, and checking resistance on tps with multimeter getting what I assume is good results as follows closed throtle: 4.32k oHms WOT: 1.286k oHms. but when I connect the black plug back into the TPS ECU reads 0voltage while no throttle and roughly when I put it to half throttle it will suddenly spike to 0.02Vs has anyone seen this type of behavior before, this is my 2nd TPS and both TPS have the exact same symptons and voltage outputs. Trying to move the TPS on the bolts placement doesn't change anything.

[Kuhaku]

Okay so if I cut the cable that is the postive from the ECU to the TPS I am getting 5volts through but as soon as I touch the wire to go back to the TPS voltage drops down to 0.102volts now, two different TPS same issue? I doubt highly is there a voltage regulator inside these TPS?

[GTSBoy]

Of course there isn't a reg in there.  It's just a pot.  If it's not working like a pot, then it's broken.

[Kuhaku]

54 minutes ago, GTSBoy said:

Of course there isn't a reg in there.  It's just a pot.  If it's not working like a pot, then it's broken.

Yeah I get the feeling I got sold a dodgy unit weird to have two TPS with the exact same failure type but no information on this being a common issue through forum posts unless I have overlooked posts, guess it is time to order a brand new one instead of second hand and see how it goes.

[GTSBoy]

The failure when reading voltage does not align with the smoothly changing resistance you measure on the TPS itself.

I suggest you test the wiring to the car/ECU more thoroughly, particularly the TPS's loom plug. You could also build your own circuit and test the TPS off the car.  Just need a stack of AA batteries to give you 6V and a little bit of wire.  Use multimeter to look at voltage across the TPS and perhaps current flowing through it (probably want another limiting resistor in that circuit too, just in case the TPS can't take all that an AA battery can provide).