Intake Air Temp Sensor

[esahuque]

There are 2 plugs that go to the stock maf. What do i do with that second plug, do i drill a hole and install it on the intake pipe or do i unplug it

[hannibal]

THe stock MAF has only one plug on it with 3 (maybe 4) wires. The other plug might be the intake air temp sensor.

[esahuque]

Yeah thats it. Now what do i do with it, unplug it or drill a hole and put it on?

[WDRacing]

It would be best to drill a hole and install it. The ecu needs to know the intake air temps.

[esahuque]

Cool deal, Thanks. I got my ECU tunned by Enthalpy, I guess that dont make a differance, does it.

[WDRacing]

Nope, still needs the signal.

[coolbone28]

Do you think it would be best to try and put it on the cold pipe so it sees the actual temp after goin through the IC? Or would the intake pipe be better.

[myRed240]

Do you think it would be best to try and put it on the cold pipe so it sees the actual temp after goin through the IC? Or would the intake pipe be better.

I, too, would like to know this....

[hannibal]

Without any other reasoning, seems like it should go next to the MAF...

[WDRacing]

I don't know anyone who runs it on the cold pipe...

[myRed240]

I don't know anyone who runs it on the cold pipe...

Just wanted to verify because I just read somewhere that it should be placed on the cold pipe.

[esahuque]

It would be best to drill a hole and install it. The ecu needs to know the intake air temps.

O.K. next problem. Air temp senser flat and the Z32 MAF adapter is round. Can't bend the senser, it will brake and can't make a flat spacer because the sencer doesn't sit all the way in like it should. So whats next, how did everyone alse do theirs. thanks for any reply's

[myRed240]

I have the HKS air filter with the replaceable filter element. What I did was unscrew the wire mesh (that holds the filter), and place the sensor under the filter. Then I replaced the filter, wire mesh and called it a day. I think it's working properly...

[rlvq35de]

I am pretty sure you dont need the intake air temp sensor. Its not used for engine driveability on 95s. Or that may just be for the HWT tune I have. I have it plugged in, but its just laying in the engine bay

[98240]

I have the aem ait sensor they say to mount it right before the throttle body. Thats were I have mine.

[lsxavier]

I had mine inside the air filter.Works fine so far.

[Edub1]

The air temp sensor compensates for cold air that is more O2 rich than normal. The measure that matters is the temp of the incoming air, so the best place for it is in the intake, before the turbo. Because it is there to avoid a lean condition, I would keep it.

[nelson8708]

the reason it is located by the maf is because it wasnt boosted from the factory. The air in the stock intake from the maf to the throttle body doesnt change temp very much...maybe a few degrees. How ever on a boosted car the air temp from the maf through the turbo (heated up) and then through the intercooler (cooled down) changed temp quite a bit. It is still probably reasonably hotter than the air coming in. Air temp will determine air density so i believe that is makes a difference but maybe just not a big one. The top of my air filter is plastic so i just drilled a few holes and screwed in into that. I am still trying to figure out how to get it some where after the intercooler but have not figured out how to yet. If anyone has any ideas on how to please share.

[98240]

The stock sensor is plastic. You could upgrade and get the aem ait sensor. It has a bung that welds into the pipe then you screw it in, connect two wires and your done.

[hannibal]

The air temp sensor compensates for cold air that is more O2 rich than normal. The measure that matters is the temp of the incoming air, so the best place for it is in the intake, before the turbo. Because it is there to avoid a lean condition, I would keep it.

I know youve been elbows deep in ECU tuning. Do you know what the ECu does with the data from the IAT sensor. Does it really add more fuel when the sensor reads cooler air?

[180sx]

Y

I know youve been elbows deep in ECU tuning. Do you know what the ECu does with the data from the IAT sensor. Does it really add more fuel when the sensor reads cooler air?

hmm fuel? last i looked correction table for iat on ka24e ecu has correction to timing map. Ambient temp will affect if it runs more/less timing. The fueling is based on what maf outputs and enrichments tps is set 2. If you were to run it you need to use it in your cold pipe to get proper temp reading past blower/intercooler.I mean having it before turbo will do, but more accurate reading is cold pipe. Ka24e doesn't have a knock sensor and iat to my understanding was used as an alternative. I didn't even think ka24de's had one, and i have no idea if that one affects fueling or not. But on my ka24e ecu i just set correction scale to "0" all across and sensor went into the garbage can. You could garbage it and just tune without , this way you tuning with max correction already in place.

[Edub1]

I know youve been elbows deep in ECU tuning. Do you know what the ECu does with the data from the IAT sensor. Does it really add more fuel when the sensor reads cooler air?

I'm 99% sure the whole purpose of the air temp sensor is to compensate for frigid temps by adding more fuel - an EFI answer to a choke so to speak. I could be wrong but when you are looking at possibly running lean on a boosted motor why not error on the side of caution.

As for the posts above - ignore the fact that temp changes after the turbo. Once O2 dense air enters the system the molecules are there for good. Higher temps will cause a rise in pressure but will not mean a decrease in O2 or "n" to be proper. I know it seems real confusing but trust me on this - it is the temp/density of the air entering the turbo that determines n, not what happens afterward. This is why spraying an intercooler will cool your air but not add O2. Only when the ambiant air is dense will you end up with more O2. This is also why an after turbo temp sensor would read incorrectly.

The temp sensor should go in it's original location if you want it to work correctly.

[180sx]

ITS A TEMPRETURE SENSOR NOT DENSITY . maf measures mass air which includes density. I am 100% possitive than on ka24e it just retards timing with accordance to scale you see in ec3 code under additinal map 3 or 4. I tested it last night with consult and ostrich.I go to correction scale and flat across set it at 10 deg. Map 5 has closed tps timing map i set it to 20 deg flat across. Consult shows me 10deg and car is ready to die. I change all corrections to 0 , consult shows 20 deg and idles ok again. i go to closed tps map again and set it 25 deg, boom consult shows 25. That was my expiriment last night on ka24e so iam more than sure thats how it works on sohc's.

[WDRacing]

Most IAT sensors are used for timing....you can even buy an adjustable rheostat piggy back thing to manually retard timing by making the ECU think you're ambient intake air is wicked hot. I've vener seen it done on the KA, but its definitly been done.

WD

[Edub1]

I haven't been able to get EC3 to work right. But how do you know that map is for that sensor? Could it be for the coolant sensor or something else?

My FSM doesn't mention the air temp sensor but it does say that the coolant temp sensor adjusts both timing and fuel - perhaps the air temp sensor is a base measure for the MAF???

Anyway, regardless of what it does, if you want to keep the original functionality it must go before the turbo or it will get a false reading under boost.

[WDRacing]

Yep...I agree. Preturbo FTW...

[180sx]

edub what problems you having with ec3 so far? works well for me displays correct timing in datascan and launch works awsome. You need to get consult and stanza ecu already dude, life will be much easier.How do i know that scale reflects the ait sensor? haha read map description in romedit . It tells you which additional map is which, like there is coolant temp vs timing .closed tps/decel timing map. and there is iat temp vs timing. Also when you use ostrich u make changes like in standalone ecu takes a split second for ecu to see updated value, and you see resaults asap. So when i go into the ait scale and start +/- 2-5deg corrections i can see the resaults on datascan as well as you can tell how motor runs with respect to timing. Changing timing affect s fueling mildly all together.And by changing iat scale i ididn't see any change on wideband.


Modified by 180sx at 11:19 PM 3/14/2007

[Edub1]

edub what problems you having with ec3 so far? works well for me displays correct timing in datascan and launch works awsome. You need to get consult and stanza ecu already dude, life will be much easier.How do i know that scale reflects the ait sensor? haha read map description in romedit . It tells you which additional map is which, like there is coolant temp vs timing .closed tps/decel timing map. and there is iat temp vs timing. Also when you use ostrich u make changes like in standalone ecu takes a split second for ecu to see updated value, and you see resaults asap. So when i go into the ait scale and start +/- 2-5deg corrections i can see the resaults on datascan as well as you can tell how motor runs with respect to timing. Changing timing affect s fueling mildly all together.And by changing iat scale i ididn't see any change on wideband.

Modified by 180sx at 11:19 PM 3/14/2007

I had EC3 hooked up but had major problems below 2500 RPMs - and I'm not the only one. Strange, perhaps I'll give it another go with my new tune and my narrow band installed.

Anyway, the EC3 is experimental and might not be correct. All we can be certain of at this point is that the changes made to that map show up on Consult. If we assume that consult is actually showing timing and that the map is correctly labeled you are correct about it affecting timing. But this still does not demonstrate that fuel is not also affected - and there are two assumptions.

I spoke to a chief engineer in the field and he explained that these things are designed by entire departments of PhDs and that many functions use numerous layers of maps that can even be multi-dimentional. It's tough to be 100% on anything at this stage in the game.

I could have sworn I saw an explaination of the AIT somewhere but regardless, it should go in the original position to ensure original functionality.

If you have Consult and a wideband try to monkey with the sensor output to simulate hot Vs cold conditions and see what happens - that is a 100% test.

[Edub1]

If you google air intake temp sensor you will get a number of explainations like the one below. I think the coolant temp sensor affects timing according to coolant temp but fuel correction is still needed under extreme air temps and that's where the air temp sensor comes in.

"Air intake temperature is used to correct fuel quantity (pulse width) since air temperature effects air density. (colder air is much more dense) Approximately 70°F is generally used for 0 correction, temperatures above will result in less fuel to compensate for the lower air density, and conversely temperatures below 70° will result in steadily richer (by volume) mixtures. Bad readings will effect ECM attempts to keep the air to fuel ratio proportional."

[180sx]

hmm ok than . i chnage the scale cell value by +10deg and i can hear it on my motor, just like when i move dizzy all the way.Change it by -10 and my car dies if i don't change it vback asap. So i am 100% sure it affects timing, even without consult readouts. Just like if i up any cell in boost area by like +5deg i can see knock reading off knocklite as soon as i hit the cell. And everything i see on consult so far can be confirmed quiet easily with timing ligh and doesn't require a room of PhD's. So far there is well over 100 cars running of eccs tunes and deviuos's and other contributor's assomptions with suceess including myself. Here is a basic test for you to do , you running oem shiet so go disconect your ait and see if there is a change on a wideband ....if not than it doesn't affect fueling or do you only listen when engeener or PhD tells you. Here another basic test stick it around your headers like real close , look at wideband what do you see ? , easy to do and no ph'd required. Also you have to understand ka24e ecu was designed back in 1985-7 so there isn't much to it and what you finding in google isn't even relative to our ait. If you so uncomfirmed about the ecu just run stanadlone AEM is only 1k. Otherwise do those basics tests for yourself and you'll see exactly what i am talking about.And ec3 works just fine for me i set map switch at 9900rpm and just edit my low's and keep high's untuched no issues under 2500, or i am never really under 2500 to notice.