CAI IAT... how important?

[raised by monkeys]

So youve probably guessed by the title, and youd be right to assume, that my IAT has fallen out of my new 3" CAI pipe, i didnt use my fail safe while in a hurry (cable tie around another hose) and it has been leaning on my headers and melted. No captain hindsights would be appreciated i know where i went wrong.

Can i just solder a new one on the existing lines?
Does anyone have one for me?

[BHDOGS]

Mine did same thing burnt it to a crisp just buy a second handy and wire the two lines back together that's what I did no issues at all since!

[b2tf]

If you can't be stuffed ordering one from Rockauto I've got one here. You can either give me $20 for it or order me one when you get around to doing it.

[Day-mow]

whats a IAT ?

[BHDOGS]

Intake air temperature sender

[Day-mow]

Ahhhhh. I see.

[auIILTD]

To answer your original question Shaun, I would say that it is pretty critical for your tune operating efficiently. Intake air charge temp is used in serveral locations within your tune, so if the value seen by your ecu is not correct, your tune will not run at it's most efficient.

Good luck with it.

Stu

[shazaam]

On another note, how would you know if it's not working and needed replacing? Would it come up on my scan tool?

[b2tf]

Originally Posted by shazaam

On another note, how would you know if it's not working and needed replacing? Would it come up on my scan tool?

It does log a fault code from memory but it does also affect the idle quality as well.

[james22]

I would also be worried about the un-metered air entering the engine (MAF sensor is before IAT). This could cause the car to run lean at WOT aswell. So until you fix it, I'd suggest blocking it off.

[GK]

Originally Posted by Day-mow

Ahhhhh. I see.

Doesn't affect us I6 owners.

GK

[b2tf]

Hey Shaun still no payment for this one? Can you PM me please, got it ready to go.

[BHDOGS]

when my burnt itself to death you could defiantly tell somethings wasnt right idle was crap and revs not so good

[Giant]

Originally Posted by auIILTD

To answer your original question Shaun, I would say that it is pretty critical for your tune operating efficiently. Intake air charge temp is used in serveral locations within your tune, so if the value seen by your ecu is not correct, your tune will not run at it's most efficient.

Good luck with it.

Stu

Good info from StuPower, Also you may find the ford IAT sensor to provide a false temp reading. Trying logging first thing on freezing cold morning and you will see what I mean. They can read at 16 degrees when the actual temp is below freezing.

Or double snap lock bag stick in freeze wait then recheck it.

I know some people use a GM IAT sensor as it reads true not sure if it will fit / work on the AU. Would be best to do some research and find out, it may have some benifits.

[auIILTD]

OK, no need for silly freezer bag tests. I have just gone and performed a test by logging the results of ACT (Air Charge Temp) with the IAT unplugged. Interesting result.

Upon startup, the ACT was equal to ECT (Engine Coolant Temp). I thought that this was interesting, but after about 30 seconds, the ACT went to a static 80 degF. IAT circuit was open circuit. You could speculate that if the IAT circuit was short circuit (ie both wires melted to extractors), the ACT would be static at a maximum value. I was not going to short the wires together for the sake of this test.

So with ACT static at 80 degF, what is this going to impact? Going through my tune I have identified some of the following functions that use ACT.

WOT Advance vs ACT - at 80 degF, no advance is pulled at WOT (on my tune - which that part should be stock), but as intake air temp goes over 100degF, timing is pulled at WOT in varying amounts (dependant on Tune). Probably not a critical factor, but timing is pulled at higher temperatures to protect the engine.

Fuel Base OL - your ACT is factor in determining your target AFR in Open Loop mode (along with ECT).

This is just a couple of functions that rely on the ACT. There quite a few others as well to do with cold startup functions. The real impact I believe is that if your IAT circuit is short circuited indicating a really high ACT, you could expect that large amounts of timing will be pulled from your tune when it doesn't need to be.

So in summary yes, the IAT is important. Not critical, but as pointed out originally, important to ensure that your tune is running at an optimum.

Cheers
Stu

[b2tf]

Might be putting my foot into something here and not to offend anybody but seriously, if it's there it is there for a reason. Leave the food storage products in the cupboard and put the damn thing back - problem solved.

[auIILTD]

Originally Posted by b2tf

Might be putting my foot into something here and not to offend anybody but seriously, if it's there it is there for a reason. Leave the food storage products in the cupboard and put the damn thing back - problem solved.

Good call Aust. Curiosity got the better of me, so I decided to do a test to see what the ECU saw when the IAT was disconnected and what impact it would have. Thought I would share my findings.

Stu

[b2tf]

Stu - nothing wrong with that, your info's actually relevant and useful. But as for questioning whether it should be there or not - well if the car came with it, I doubt that'd be because someone at Ford had a whole heap of IAT's left over and decided to get rid of them one by one.

Anyway Stu keep learning so you can tune my barrow

[Giant]

Originally Posted by auIILTD

OK, no need for silly freezer bag tests. I have just gone and performed a test by logging the results of ACT (Air Charge Temp) with the IAT unplugged. Interesting result.
Your ment to test the ACT with IAT plugged in. When the engine is cold and cross reference it against the ambient air temp.

Upon startup, the ACT was equal to ECT (Engine Coolant Temp). I thought that this was interesting, but after about 30 seconds, the ACT went to a static 80 degF. IAT circuit was open circuit. You could speculate that if the IAT circuit was short circuit (ie both wires melted to extractors), the ACT would be static at a maximum value. I was not going to short the wires together for the sake of this test.

So with ACT static at 80 degF, what is this going to impact? Going through my tune I have identified some of the following functions that use ACT.

WOT Advance vs ACT - at 80 degF, no advance is pulled at WOT (on my tune - which that part should be stock), but as intake air temp goes over 100degF, timing is pulled at WOT in varying amounts (dependant on Tune). Probably not a critical factor, but timing is pulled at higher temperatures to protect the engine.

Fuel Base OL - your ACT is factor in determining your target AFR in Open Loop mode (along with ECT).

This is just a couple of functions that rely on the ACT. There quite a few others as well to do with cold startup functions. The real impact I believe is that if your IAT circuit is short circuited indicating a really high ACT, you could expect that large amounts of timing will be pulled from your tune when it doesn't need to be.

So in summary yes, the IAT is important. Not critical, but as pointed out originally, important to ensure that your tune is running at an optimum.

Cheers
Stu

I agree you should always run the IAT.

My point which i failed to make clearly was more aimed at tuning / performance. The genuine ford IAT sensor can often give a false high reading of the ACT. This would means your tune is not using a true reading to work out when and how much timing to be pulled etc.

So it could be costing your power / tuning accuracy.

The snap lock bag / freezer test is just one way to lower the temp of the sensor to a known temp and then see what the volts read and cross reference this to see what volts that temp equals. Or plug it back in to the car and see what it reads on the data logger.

When you finish testing it you plug it back into the car before driving it.

As you can read in my original post I said you can just do it in the car on a cold morning or as Stu did.

The better sensors perform and the faster they react to changes and provide accurate readings the better your data logging and tuning should be etc.

Probable makes little difference to the daily driver.

Cosworth and GM IAT sensor can be a better option for tuning.

I hope this clears things up and that I actually made sense this time

[auIILTD]

Originally Posted by GIANT

Your ment to test the ACT with IAT plugged in. When the engine is cold and cross reference it against the ambient air temp.

No Matt. My test was to see what the result was if there was NO IAT. We are not testing the accuracy or performance of the IAT, but addressing the very subject of this thread. Nowhere in this thead has the accuracy been discussed or queried.

[Giant]

I understood your test. I also though its important to get correct readings. Just delete any of my post that are not relevant to the thread.

http://oldfuelinjection.com/?p=29 This link may help if he wishes to test the new sensor is working correctly.