is it as straight forward as putting an ohms metre on the connections to test the circuit? Anyone done ht or can suggest any other way of testing it?

 

What car/engine/ecu ?

 

its an 94 toyota celica gt4 has problems starting bad idle and runs pretty shite?

 

Ahh ! Sorry I cant help you with exact technical information.

If it was a Ford then no problem..LOL

Probably better to ask on the Celica owners site as they will have done it all before !

 

yeah your probably right pal

 

bttt for any toyota fans

 

Toyota fans on a FORD site good luck.
on a side note Flux capacitor, how would you test the TPS on a big turbo escort cosworth. Just incase i ever get dramas with mine.

 

passionford caters for all usually lol

 

just not toymota,s as it seems

easiest way personally is buy a new one cheapskate surely cant be that much

 

Would probably need something that could show it in a graph or something? So that any deviations from the linear increase/decrease would be visible. Just guessing though.

Would a oscilloscope or whatever they are called work?

 

not my car so im not buying him a new one, i googled it and theres you tube vids them being tested with metres so i'll give it a go

 

Probably just a crude variable resistor, so as the throttle position changes, so does the resistance of the sensor so the ECU can work out at what position the throttle is.

So yeah, I'd try an Ohm meter first off to make sure it isn't open circuit.

 

the celica's have a sequence of fault lights, which tell you what is wrong, or has come up as an error

use google to search on how to do it

 

Thats the best way measured at the ecu input pin


Excluding a small turbo escort cossie.....

The cossie TPS is not a straight forward poteniometer.
When at idle, the wiper does not make contact with the resistor.
As you apply movement, the wiper starts to touch one end of the resistor and then moves to the other like a normal potentiometer.

The outer pins are the resistor and can vary from about 1000 to 5000 ohms depending on type and age.
The escort will be around 4700 ohms.

The centre pin is the wiper and movement should cause a resistance increase on one outer pin and decrease on the other depending on direction and which outer pin you choose to test against.

Pin 17 on the weber ECU is the throttle input.

Use pin 11 as the earth for a voltmeter and oin 17 for positive.

4x4 vehicles (L8/P8) will have a voltage of about 0.1-0.5 volts at idle and 4.5 to 5.1 volts at full throttle.

2wd (L1/L6) will have a voltage of about 4.5 to 5.1 volts at idle and 0.1 to-0.5 volts a full throttle.

(Voltages given are rough taking into account measurement tolerances..etc)

Check the readings change smoothly when moving the throttle very slowly .
Any sudden jumps...change the sensor !

Assuming the Throttle butterfly and cable are ok, the best way to align the TPS to the throttle body is to loosen the 2 screws so the sensor is free to move by itself a bit and disconnect the loom.
Open teh throttle fully and allow it to snap shut by taking your foot of the pedal fast.
Then check the sensor rotates and springs back cleanly. Tignten screws, reconnect loom.

Hope that helps if only a breif explanation..lol

 

Thank you FLUX.