2JZ GTE intake temp sensor replacement

[Swampy442]

I learnt from tuning the Supra that the intake temp sensor is a weak point in terms of response and hysteresis, so could you fit an aftermarket sensor and the stock ECU will be OK with it?

[johnny g]

Probably only if the voltage response curve is the same...

[jagman]

You could replace the sensor , the Ecu has an internal fixed resistor and this is paired with the external resistance of a thermistor - sensor , this produces a voltage that equals the temp , very small voltage like 0.1 to 4 volts that equal the temp . It is non linear resistance ,I sure the numbers are in the manual . Quite a wide tolerance is considered serviceable . Fast reactance is considered to be below 0.5 seconds - don’t know what the stock sensor is , but sensors are available in a few ranges of resistance and seldom will be unique . Some are chip based now and tiny . I guess a durable one needed that matches the curve will work fine .

[Swampy442]

I just know from talking to people that the reaction times of the stock sensor are pretty poor. Ive no tuning plans but just wondered if it could be an actual upgrade to the stock management

[mattdavies]

It might be worth a look on the Supraforums ( US ) as i seem to remember they have worked out how to insulate it better. that might be an aftermarket sensor though 

[jagman]

I think on the stock ECU there is little benefit , as the control strategy is fixed and cannot be altered but on an aftermarket ECU you can add further use strategies . Heat soak strategies and part of a det strategy and water injection strategy. Any delay I don’t think will make that much difference at stock power levels ,the delay won’t be that slow . The stock ECU will use fixed temps as points to intervene rather than a sliding scale that an aftermarket Ecu can alter at a finer level . I guess there are not many tuners fully understand the control strategies and have solid data but use what they have altered previously . Heat soak - for example ,if you know the sensor is going to heatsoak when car is at idle or after a power event , you can use other data points like throttle position or oil temp and factor those in ,I doubt the stock ECU has any ability to change these at all from factory program 

 

[johnny g]

And lets not forget the ECU will be late 1980s / early 1990s design with (very) limited capabilities compared to now.