TPS

[FLESHAXXE]

Does anyone have the wiring diagrams for both silvertop and blacktop ...the ST has four wires comming from it and the BT has three..

[sergei]

Does anyone have the wiring diagrams for both silvertop and blacktop ...the ST has four wires comming from it and the BT has three..

I believe black top is missing IDL switch in the TPS. Rest is just a potentiometer (GND, position, +5V).

[RomanV]

I've got a blacktop 4AGE throttle set and TPS, and it's 4 pin?

The 4th pin is just a switch that tells the ECU when the throttle is completely shut, presumably for idle speed control or something.

[sergei]

I've got a blacktop 4AGE throttle set and TPS, and it's 4 pin?

The 4th pin is just a switch that tells the ECU when the throttle is completely shut, presumably for idle speed control or something.

The plug on blacktop is missing one of the wires (for the IDL switch). I am not sure but there is possibility that the actual TPS has it in place.

[FLESHAXXE]

The reason for asking this is because as it is right now, when I go hard throtle the car bogs down .When it is disconnected the car revs and drives much better.I have taken the blacktop computer and tried it in three other levins and they work fine,I have also changed the TPS and the same thing is happening....I'm thinking that somehow the wires going into the TPS from the harness needs shifting around....

[iOnic]

3 wire TPS is just a switch - Only tells the ECU if the throttle is open or closed - not how much. The MAP sensor tells it everything else it needs to know about how you are accelerating.

4 wire TPS is a true potentiometer and tells the ECU exactly how much throttle you're giving it so it can make changes.

First step make sure you have good earths for the TPS and MAP sensor. If the ECU works fine in other cars and you've tried a good TPS in yours with no change then the fault is in the wiring on your car - usually earths. If you can find a workshop manual you can test the TPS with a multimeter and that should point out wiring faults pretty quickly - doesn't have to be a ST/BT manual - most Toyota TPS's are the same aside from the 3/4 wire difference.

[sergei]

3 wire TPS is just a switch - Only tells the ECU if the throttle is open or closed - not how much. The MAP sensor tells it everything else it needs to know about how you are accelerating.

4 wire TPS is a true potentiometer and tells the ECU exactly how much throttle you're giving it so it can make changes.

Not entirely true.

3 wire can be true potentiometer just like in black top where pin #3 is not connected (vs silvertop), pin #3 on silver top is IDL switch (tells ECU throttle is shut).

Basically on black top:
#1 is 5V supply (yellowish wire)
#2 is position output, 0.5V shut, variable to 5V - open
#3 is missing (but in silvertop it is IDL switch)
#4 is ground (brown wire)

[matt dunn]

stuff

most cars that are 3 wire and switch only are 90's nissans.

almost anything modern or automatic trans have a variable potentiometer.

[RomanV]

3 wire TPS is just a switch - Only tells the ECU if the throttle is open or closed - not how much. The MAP sensor tells it everything else it needs to know about how you are accelerating.

4 wire TPS is a true potentiometer and tells the ECU exactly how much throttle you're giving it so it can make changes.

Not true, I've tested 20V TPS with a multimeter and it's definitely a true potentiometer, not just a switch.

It's probably all the more relevant on a quad throttle engine, where the MAP signal possibly aint so great at some load/rpm conditions.

I'm pretty sure even gen 2 3SGE TPS is a 3 wire potentiometer.

[RomanV]

The plug on blacktop is missing one of the wires (for the IDL switch). I am not sure but there is possibility that the actual TPS has it in place.

Yeah, now that I think about it, I was probably using the 4 pin plug from a silvertop, on blacktop TPS.

The blacktop TPS still has the switch built into it as well, even if it's not used. If that's of any use for aftermarket ECUs or whatever.