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Unread 01-11-2011, 10:21 AM   #16
Bigbob
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Quote:
Originally Posted by never monday View Post
plug the sensor in and zip tie it out of the way in the engine bay
That would be very helpful. Maybe just splice the wires together. While you are under the hood pull the dip stick and toss it out. Just crimp the tube shut so dirt don't get in. I've done this and no codes were thrown!
Just cause it don't throw a code right away does not mean you dont need it. The IAT and it's function is key in setting your fuel mixture to it's optimum both for power and economy.

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Unread 01-11-2011, 10:26 AM   #17
never monday
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Quote:
Originally Posted by Bigbob View Post
That would be very helpful. Maybe just splice the wires together. While you are under the hood pull the dip stick and toss it out. Just crimp the tube shut so dirt don't get in. I've done this and no codes were thrown!
Just cause it don't throw a code right away does not mean you dont need it. The IAT and it's function is key in setting your fuel mixture to it's optimum both for power and economy.
what are you saying?

quantify the difference in temperature between the are 1" around the grill support rod on the passenger side. And the inside of the air tube.

The factory mounts the IAT sensor inside the tube so it has filtered air and preserves the life of the sensor. As a short term measure to keep his engine operating properly. RECONNECTING the sensor and zip tieing it out of the way. Will still give the engine the necessary under hood temps it is looking for.

I just went and read your other post.
Are you aware that after prolonged low speed or idle running time. An insulated intake system will also heat soak. The insulation is real good at keeping heat in as well as out.
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Unread 01-11-2011, 11:03 AM   #18
55willystruck
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I have to agree with the above. I wrapped my tube and mustang box in some DEI wrap and ran it for a while like that. I don't have any scan guage or fancy crap like that but was surprised that after doing several things under the hood on a warm day after a lot of driving, when I pulled the heat-wrapped air tube off, it was cool to the touch on the OUTSIDE where the nice shiny foil stuff was, but on the INSIDE the tube itself was actually quite warm, almost hot in fact. I've since pulled the tape off the box, and likely will pull it from the tube as well-mostly because I need to change some things again and it's in the way. I guess what I am saying is once I pull it, I won't go to the trouble of putting it back on again. Also removed all the DEI header wrap type stuff from all my fuel injectors and fuel rail as well. On a really HOT day in HOT temps, almost made the misfire worse. Not sure if that was it, or contributing but I wasn't convinced it was helping so off it went.

With a cowl intake though and larger diameter tube flowing to TB, I gotta THINK at least the air is moving fast enough through to not be as effected by heat soak from the engine. Could be wrong, again, don't have that fancy guage thing, just a guess. I cut the factory air tube in half for kicks and was surprised it was over 1/2" thick, leaving a quite small diameter tube through the middle. Lots of material to sit and heat soak for sure there, then cook after shutdown-not that it matters, just something I noticed with some of my tinkering.

Been stupid cold here for a while now. Economy sucks worse than ever, combined with the stupid misfire, gets frustrating.

Best of Luck,

Mike
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Unread 01-11-2011, 11:41 AM   #19
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Quote:
Originally Posted by never monday View Post

quantify the difference in temperature between the are 1" around the grill support rod on the passenger side. And the inside of the intake?.
The IAT measurses intake air. It was not meant to measure engine bay air. The computer does not care what the engine bay air temp is. It does care about intake air.
Quote:
Originally Posted by never monday View Post
The factory mounts the IAT sensor inside the tube so it has filtered air and preserves the life of the sensor. As a short term measure to keep his engine operating properly. RECONNECTING the sensor and zip tieing it out of the way. Will still give the engine the necessary under hood temps it is looking for.

.
I think filtered air and dirty air would be the same temperature in the same area. If the wanted to protect it from dirt why not just coat it? LOL. I like to keep my CD's clean, but I don't stick them in the intake!

Quote:
Originally Posted by never monday View Post

I just went and read your other post.
Are you aware that after prolonged low speed or idle running time. An insulated intake system will also heat soak. The insulation is real good at keeping heat in as well as out.
True. The intake can heat soak at idle or after shutdown. But if you are pulling actual outside air in it wl be much cooler. Engines like cooler denser air. Anything that can be done to achieve this (within a reasonable price range) should be done. If you are pulling that nasty under hood air in that is hot the intake will naturally heat up. If you pull in the much cooler, especially while parked and idling, air from the outside you will alway benefit from a insulated intake tube. This has all been tested. Jeep guys razz the words "CAI" as 99% of what is sold gets the air from under the hood! No benefit in that. You need that cooler outside air and let it tell the IAT sensor pass the info on to mother computer. Try it and you will like it
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Unread 01-11-2011, 11:49 AM   #20
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BTW. On the subject of heat sink. In 2005 Jeep finally moved the IAT sensor from the intake manifold to the air tube. More heat sink issues with it in the manifold. You will find that most guys with 2005-2006 Jeeps get a little better mileage. Still terrible, but all things being equal performace improved.
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Unread 01-11-2011, 01:30 PM   #21
never monday
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Quote:
Originally Posted by Bigbob View Post
The IAT measurses intake air. It was not meant to measure engine bay air. The computer does not care what the engine bay air temp is. It does care about intake air.
um....last time I checked the factory intake was in the engine bay.


ANY air reading is better than NO air reading.
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Unread 01-11-2011, 02:03 PM   #22
stuff2c
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hell if it likes cold air move the beer over and stuff in in cooler... just say'n
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Unread 01-11-2011, 04:39 PM   #23
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Quote:
Originally Posted by never monday View Post
um....last time I checked the factory intake was in the engine bay.


ANY air reading is better than NO air reading.
Correct. The OP does not have a factory intake. The factory intake sucks air, hot air from under the hood and right behind the radiator.
His intake takes in air from outside of the engine bay and is cooler than what a stock set up sees. And he wants to insulate the metal tube to help keep it cool.
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Unread 01-11-2011, 04:49 PM   #24
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Originally Posted by stuff2c View Post
hell if it likes cold air move the beer over and stuff in in cooler... just say'n
Yup. Good, but not practical. And warm beer is just sad beer.
That is the object of a intercooler on a turbo engine.
Cooler, more dense air.
Back in the day many drag race types packed ice on top of their intake manifold. They even made systems that worked similar to an intercooler but instead of air passing though they were packed in ice.
Of course they used that good outside air not the nasty hot stuff under the hood.
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Unread 01-11-2011, 04:55 PM   #25
never monday
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Quote:
Originally Posted by Bigbob View Post
Correct. The OP does not have a factory intake. The factory intake sucks air, hot air from under the hood and right behind the radiator.
His intake takes in air from outside of the engine bay and is cooler than what a stock set up sees. And he wants to insulate the metal tube to help keep it cool.
"I installed an intake this weekend. There was no bung for the ATS. I left it the pigtail taped out of the way and covered up. The sensor is in bubble wrap in the glove box."

This needs to be remedied first, as in NOW, right NOW. Attach the sensor to the wires and secure it out of the way.

The computer needs a temp signal, ANY signal
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Unread 01-11-2011, 07:46 PM   #26
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All's well that ends well.

Skinnypedal was VERY helpful and put a grommet in the mail that day (Monday). I also got a link to an updated pdf that shows the step associated with drilling the intake. I did not want to wait for the mail, so I did some measuring and went to Ace Hardware. 3/4" groove ID, 1/2" ID hole grommet: $.85.
I bought two. The calipers said the sensor was .55 inches diameter. As there is going to be SLIGHT vacuum in the tube, and it was a tight (albeit uncrimped) fit, I felt pretty good. It took 10 minutes.
I cleared the code, fired her up, and rode away. I will check for thrown codes between key cycles every now and again (Do Jeeps store them but sometimes not display them if they don't meet spec for MIL? Nissans do...)

I drove 34.3 miles without a sensor plugged in. All indications are that Jonny Jeep is correct. It thought I was getting air at -40 degrees Celsius, because it returned about 12 miles to the barrel.

I am going to leave it unwrapped. One of the main reasons to wrap headers was to keep heat in the exhaust so that it would move faster, giving better evacuation of the cylinder, not to keep everything else under there cooled off. Much the same way that Coors abandoned the insulated can (it takes too long to cool down when it is warm), I am convinced of the laminar flow and mass of the air charge avoiding hanging around and heating up.

Thanks for everyone's time and attention.

--crimedog
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Unread 01-11-2011, 08:17 PM   #27
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Originally Posted by crimedog View Post

I am going to leave it unwrapped. One of the main reasons to wrap headers was to keep heat in the exhaust so that it would move faster, giving better evacuation of the cylinder, not to keep everything else under there cooled off. Much the same way that Coors abandoned the insulated can (it takes too long to cool down when it is warm), I am convinced of the laminar flow and mass of the air charge avoiding hanging around and heating up.

Thanks for everyone's time and attention.

--crimedog
Ah, but the air in the intake will be colder if wrapped. Dr D on the Rubicon forum did a pretty detailed test on this and it did indeed make a difference.

You are gonna like your set-up. How is the sound?
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Unread 01-11-2011, 08:46 PM   #28
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i can only imagine the comment about putting the sensor in a baggie was a short term solution. As pointed out, running without a sensor 1) bottoms out the snesor table (- reading) and causes fuel/timimg issues 2)since there is no current flow sensed by the PCM, it will likely toss a code.

Also, about the heat soak...there are 2 battles to fight. Insulating the tube from hot radiant air, and heat soak from physical contact. If you get quality products that do not conduct heat, you can lower the contact soak. If you use insulation wrap, you cut down on radiated heat soak. Add them together, and thats where you make a differece. But, as mentioned, wrapping a tube that is getting directs contact heat transfer is likely going to have little or even adverse effects since the insulation will trap the heat in the tube.
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Unread 01-11-2011, 10:51 PM   #29
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Post Taco Stress Disorder.

I have run to the market to get the right taco seasoning in my jeep.
Quote:
Ah, but the air in the intake will be colder if wrapped. Dr D on the Rubicon forum did a pretty detailed test on this and it did indeed make a difference.

You are gonna like your set-up. How is the sound?
BigBob, I will reserve judgment on the wrap until I have read Dr. D's study. Keep in mind that this was a gift, a gift to help me find some lost mpg. I'd like to get back over 15.5 again. The wrap may help, but I am only looking to reduce pumping losses, not run the quarter-mile.

The sound is great. Throttle response is great. I can react to A#@holes (like they can't see a black Jeep on 33's) with less worry about the lag between foot and movement.
Quote:
i can only imagine the comment about putting the sensor in a baggie was a short term solution. As pointed out, running without a sensor 1) bottoms out the snesor table (- reading) and causes fuel/timimg issues 2)since there is no current flow sensed by the PCM, it will likely toss a code.
Texan32, it was short term until I could talk to Spectre. I took care of it today. I did not get any fuel/timing codes. I know I was running rich, but not long enough to worry about long term motor damage (34 miles, never @ WOT). The only code I got was "Bad IATS", which isn't terrible, considering it was missing.

Jeeps are OBDIII or later, right? One of the, what, 4? downstream O2 sensors (pre-cat ones, anyway) had to be playing with AFR and ignition timing. That is their whole purpose. I just don't know how much control the ECM gives it. Jonny Jeep's Chart shows bottom at -40 deg C. I was driving in -10 to 0 deg C., so it isn't that far off. It is not as if I installed this when it was 40 degrees C.

Regardless, I will jump over to the Rubicon section (or is there a seperate website for their forum?) and look at Dr. D's study....
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Unread 01-19-2011, 07:53 AM   #30
crimedog
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Reasons to avoid taping it out of the way.

Quote:
Originally Posted by never monday View Post
"I installed an intake this weekend. There was no bung for the ATS. I left it the pigtail taped out of the way and covered up. The sensor is in bubble wrap in the glove box."

This needs to be remedied first, as in NOW, right NOW. Attach the sensor to the wires and secure it out of the way.

The computer needs a temp signal, ANY signal
I disagree. Of the two conditions, lean and rich, rich is the least damaging to the engine. Reminder, this was short term.

1. Were I to attach it and secure it out of the way, it would read much warmer air than that which it is receiving (via cowl-air-induction) because it is sitting stagnant in the engine bay. We are having a cold snap here in VA, so I would get a lean condition, something that lends itself to pre-detonation and other bad things.

2. Leaving it unattached gives the coldest reading and, therefore, max fuel. This is inefficient in many ways, and only mildly controllable via downstream O2 sensors, but it avoids lean.


First full tank with sensor attached is looking good. Further bulletins as events warrant.


Now when was the last time I changed spark plugs.....
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