Air Intake Temperature Sensor 3200 GT

[Boomerang_GT]

I was wondering if anyone had problems with or due to this sensor.
I just found out by coincident that mine is not working at all. Should be around 2.5 Ohms at 30 degrees Celsius, but mine does not even have any resistance, means open circuit.
I had the feeling that the 3200 GT of a friend has more power and better throttle response than mine. Mine also had d limp mode from time to time.
But strangely mine consumes less fuel (around 11-12 liters) than his (14-15L).
I just ordered a new sensor that should arrive tomorrow.
Just curious what effect it could have with regards to the fuel mixture.

 

[davy83]

Well you have stirred up a storm of responses here!!!
I have not had problems with this sensor my self. However being a turbo charged engine the air temperature is almost certainly there for two reasons. I would think

First it will be a safety measurement to make sure the gases entering the plenum are not too hot, since they will pick up some heat going through the turbos. The intercoolers should reduce the air temperature and I suspect this temperature sensor is verifying this is true. The ECU may reduce engine power if it thinks the gases are too hot? Not sure, I am not aware of anyone experiencing this. However the 3200 can be complicated thing to work on and its possible this might get missed even if it was happening.

Second the density of air changes with temperature and with the 3200 we are compressing the air so this alters its density quite a bit too. whether the ECU can make any serious measurement as to the air density (and use this to control the fuel injection) from this I am really not sure, the turbo being up stream from this point and this both compresses the air and also heats it up by conduction and by virtue of the compression, so its possible the temperature can indicate the efficiency of the turbos? you would need intake air temperature too I suspect and I am not sure there is an intake temperature sensor? So I think where I am going with this is that its possible this sensor being faulty would mean the ECU will get the engine tuning wrong and make your car slower but its seems quite unlikely since this would suggest a pretty complex measurement and control system, and I dont think it is.

What did your car do with this sensor faulty?

I guess i could replace the sensor with a variable resistor and see what my car does when this does not read right, but I fear I would anger the italian sports car gods and my car would simply self destruct, its bad enough that I run all these pedal sensor test runs.

Not sure if any of this rambling was what you were looking for!!

 

[Boomerang_GT]

Thanks Davy for your very interesting input!
I don’t know for how long it hasn’t been working, but at last years mot, they said that building up the right lambda ratio was too slow.
So I replaced the lambda sensors.
Now after changing the temperature sensor, I can say that the car Starts much better when hot and has a much better throttle response.
Also driving until max rpm feels smoother.
But not much change in power.
Regarding the air intake temperature sensor, I think it’s the outside air temperature sensor that is taken as reference. Had quite some limp modes when mine was broken.

 

[Nikue]

Im surprised you had better fuel economy with the sensor not working. But maybe you have a lighter right foot.

There again it could be the fact that it was not as powerful due to sensor failure and open circuit that meant it used less fuel.

 

[Boomerang_GT]

I could imagine that it might have been running lean.
But now that my friend changed his open blow off valves to oem, he reports a better fuel economy.
So that might have been the reason.
Still my car finally starts much better.
Cheap and easy fix

 

[davy83]

Not sure about running lean, but the faulty sensor most probably caused the ECU to select "safe" mixture settings because a piece of information was missing and this means less power and less fuel.
AS you say easy fix, if only all 3200 problems were so easily solved!!