MAT Sensor Relocate

[SnakeOiler]

In most applications, just relocating the IAT (that's "intake air temperature") sensor makes little or no difference in performance if the testing is done properly.

Based on the subject, I just had to read to find out what a 'MAT' sensor was.

Thanks Hib for setting it straight. I've never heard of anyone referring to it as a MAT sensor.

 

[Superc63]

IAT Sensor Moved

The only reason I am planning on buying one and putting it anyplace other than the stock location is ease.

I am not looking for any performance gain.

As far as what I meant by an accurate reading...essentially they temp sensor should read about ambient air temp.

Granted, ambient air temp in the manifold is probably hotter than over near the battery...but it is probably close enough.

Right now, the car is hard to start when cold because I think my sensor is shorted. As soon as I unplugged that sensor, starting got way better.

Chris

 

[aklim]

As far as what I meant by an accurate reading...essentially they temp sensor should read about ambient air temp.

Right now, the car is hard to start when cold because I think my sensor is shorted. As soon as I unplugged that sensor, starting got way better

There usually are 2 ways to do something. Doing it right and cobbling it. It is more relevant to the readings when you do it right.

That might mean there is more enrichment but that is not to say that is the answer. 84 is a cross fire so it has 2 injectors. Maybe one is on the way out. You need a scanner to find out what the ECM is seeing. If it sees the correct ambient temp, all disconnecting it does is mask the problem.

 

[mseven]

One is a simple devise that sends an upgraded signal from the o2 sensor by way of an adjustment, and a little box that adds or subtracts volts that are essentially what the ECM sees from the o2 sensor. It can be adjusted for full lean or full rich depending on what you;re doing that day. It was a radio-shack build it yourself kinda deal, so I never got much past the drawings...but it seemed possible.

and why would anyone want this ??? I would seriously hope that no one would actually try to manipulate the mv. readings in that fashion.

Based on the subject, I just had to read to find out what a 'MAT' sensor was.
Thanks Hib for setting it straight. I've never heard of anyone referring to it as a MAT sensor.

Manifold Air Temperature or MAT sensor ...that is the acronym used by GM in the fsm (Factory Service Manual)for 90-91.

Right now, the car is hard to start when cold because I think my sensor is shorted. As soon as I unplugged that sensor, starting got way better. Chris

A scanner or software and a laptop would reveal what is really going on with not only that sensor but other potential problems.....failure in the mat circuit should set a code 23 or 25 (before unplugging of course).

 

[aklim]

and why would anyone want this ??? I would seriously hope that no one would actually try to manipulate the mv. readings in that fashion.

Manifold Air Temperature or MAT sensor ...that is the acronym used by GM in the fsm (Factory Service Manual)for 90-91.

A scanner or software and a laptop would reveal what is really going on with not only that sensor but other potential problems.....failure in the mat circuit should set a code 23 or 25 (before unplugging of course).

People will do cheap and easy fixes if they even get a hint that they can get away with it. Why do you think that they sell the battery operated supercharger or the Tornado?

Which one calls it the IAT (Intake Air Temp) sensor?

Shouldn't it set that code only if it falls outside the parameters? Not sure what the window is though.

 

[mseven]

People will do cheap and easy fixes if they even get a hint that they can get away with it. Why do you think that they sell the battery operated supercharger or the Tornado?
Which one calls it the IAT (Intake Air Temp) sensor?
Shouldn't it set that code only if it falls outside the parameters? Not sure what the window is though.

I know that ford and mazda use the acroynm IAT, and I believe that GM switched to that terminology once the OBDII stuff began.

Codes 23-25 window/s parameters
code 23: is set when mat signal voltage temp. stays below -30c for 1 second, engine run time 2 min. and no vss signal,
or,
ignition on, engine not running, coolant greater than 60c, but mat signal voltage showing manifold temp below -30c.

code 25: run time 2 min. (or more), no vss, car not moving, and mat signal voltage showing a temp greater than 150 c.
or,
and vss signal present with greater than 5 mph., and mat voltage indicating a temp greater than 150 c.

Correct, it will be set when outside the above window/s. We and or the poster would not know this without either a scan or checking for codes at the very least. I agree with, and prefer with using a scan device of somesort, as it is easier than looking sensors over with an ohm meter and one can see it under operation (which in the case of an 02 is really the on;y way to understand if it is functioning properly). I have an auto x but on these cars I prefer the laptop with datamaster, tuner pro, or hp tuner etc. depending on the version/year of the car.

 

[Hib Halverson]

You end up picking up cooler air (denser air mixture) to be read by the sensor.

Cooler air should be better compared to the hotter air at the position of the original sensor.

Cooler = denser = more power!

Faulty logic.

The engine will not get cooler, more dense, air after you move the intake air temperature (IAT) sensor. All that happens is the ECM may "see" an IAT reading which is, at some times, lower than it did before the sensor was moved. Depending on the ECM calibration, when the ECM sees lower IAT data it may allow more aggressive spark timing.

If the engine can use that more aggressive timing, the engine may produce a little more power. If the engine can't use that extra spark, ie: it goes into detonation, EST will retard the spark and there will be little or no change in performance.

Lastly, the purpose of the IAT sensor is not to measure ambient air temperature. It is to measure the actual temperature of the charge air going into the intake manifold.