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Intake Temperature Low?

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Old 08-29-2016, 01:14 PM
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Default Intake Temperature Low?

I was reading the OBDII outputs from the torque app on my 2002 T/A today and I noticed that my intake temperature was reading 35 degrees fahrenheit. I find this hard to believe, since my engine was at idle after driving for a half hour, coolant temp sitting at 200 degrees, outside temp at 90 degrees, and I don't have a cold air intake. I've had some strange idle issues lately but nothing really serious, but I'm wondering if this could be a contributing factor?

Here's some of the other data I wanted to double check with you guys, and see if any of it seems out of the ordinary. I know the o2 data is but I've always had codes for that.

Intake temp 35F
Intake pressure 4.9psi
Timing advance: 31
Throttle 0.0% (Doesn't 0.0% mean stalled?)
o2 1 1-2 0.05v
o2 2 1-2 0.04v
Maf cfm 60
Old 08-29-2016, 02:09 PM
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IAT sensor seems to be giving false readings. Might be time for a new one.

0.0% for throttle percentage is normal at idle. TPS voltage should be slightly above 0 though, about 0.4-0.6v would be normal at idle.
Old 08-30-2016, 06:18 AM
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Are you SURE the temperature its giving you is not in Celsius? -> Because 35C would be a correct value.
Old 08-30-2016, 08:05 AM
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Originally Posted by wssix99
Are you SURE the temperature its giving you is not in Celsius? -> Because 35C would be a correct value.
Positive. I thought the same thing so i double and triple checked it. It could be a bug in the app though.

Last edited by TallgeeseIV; 08-30-2016 at 08:46 AM.
Old 08-30-2016, 09:56 AM
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Originally Posted by TallgeeseIV
Positive. I thought the same thing so i double and triple checked it. It could be a bug in the app though.
Yea, that would be some coincidence. If you take an ohmmeter to the IAT, you can confirm the resistance and check the temperature manually. If my memory serves me, there are only two main types of elements these things use and you an just google "IAT resistance" to get tables of the cross references to temperature. That will confirm if the sensor is bad.
Old 08-30-2016, 10:35 AM
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So its specific reading via the app is 35.6F. It started at that, and does not change while moving, idling, stopped in the shade or sun, nothing. So I think it's stuck... Probably since winter. The part was only like $8 on amazon so i ordered it last night and it'll be here tomorrow.

Last edited by TallgeeseIV; 08-30-2016 at 11:42 AM.
Old 08-31-2016, 11:59 AM
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So I changed out the sensor and it's still reading 35.6F, even with a different scanner, so I'm thinking it's a wiring problem. Anybody have instructions for how to find the bad wire for the iIAT? I've never been good at this part.
Old 08-31-2016, 12:32 PM
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First, what does the scanner tell you the temperature is when you have the senor unplugged? When you have a jumper wire across the two terminals? (Instead of the sensor.)

In a normal world:
- Unplugged, you should see an error or super cool temperature.
- Plug terminals jumped, you should see a super hot temperature.

Depending on this ^ we might be able to figure out what is going on.
Old 08-31-2016, 07:43 PM
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wssix has got you on the right track. Before going crazy, make sure the wires at the connector aren't broken. The wires kind of just hang there, so most likely it they'll be broken right at the connector. Wiggle them around and pull on them, you should be able to identify a break.

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Here's a schematic if you can't find anything. You'll have to test for continuity between the wires from the PCM to the IAT
Old 08-31-2016, 07:50 PM
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Thank you all for the help, but I found the issue.... Check out what I found plugged in between the sensor and the harness. Completely overlooked it before:



IAT Faker...

Thank you especially to wssix99! If you hadn't told me to jumper the connections I probably never would have noticed that that wasn't the stock connector. I bought this car 10 years ago and I'm STILL finding mods the original owner did...

Last edited by TallgeeseIV; 08-31-2016 at 08:20 PM.
Old 08-31-2016, 08:26 PM
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SLP timing tricker? Haha. I actually thought of that early on and was going to post about it, but then didn't because I assumed this condition was something new that had just developed for you. And obviously you would know if you had installed such a device. Interesting that you just discovered this after so many years.
Old 08-31-2016, 08:29 PM
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Originally Posted by RPM WS6
SLP timing tricker? Haha. I actually thought of that early on and was going to post about it, but then didn't because I assumed this condition was something new that had just developed for you. And obviously you would know if you had installed such a device. Interesting that you just discovered this after so many years.
Well I've had a bluetooth OBDII reader for a while but I never really put much effort into reading the raw data and just stuck with the gauges in the torque app. honestly i figured if there was a problem with the data i'd get a code for it. not always the case of course.

I've been helping my roommate rebuild a neon srt4 and he had a major issue causing high idle after getting it back together so i suggested taking a reading of the raw data and comparing it to what it's supposed to be from posts on his forums and we found a massive intake manifold leak that way. So i figured hey, my car's been running strange forever, i wonder if that'll work for me.

so i did and that value looked off to me, so i posted about it. and bam, here we are.
Old 09-01-2016, 02:29 PM
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Originally Posted by RPM WS6
SLP timing tricker? Haha. I actually thought of that early on and was going to post about it,
I was thinking to myself, "How is this possible???" I couldn't think of how this thing or circuit could fail with a constant middle-of-the-road resistance. So, I figured - let's unplug the thing and see if there are aliens chewing on the wires...

I assume the intent of this "timing tricker" would be for temporary use at the track and not for steady state driving?
Old 09-01-2016, 03:08 PM
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Originally Posted by wssix99
I was thinking to myself, "How is this possible???" I couldn't think of how this thing or circuit could fail with a constant middle-of-the-road resistance. So, I figured - let's unplug the thing and see if there are aliens chewing on the wires...

I assume the intent of this "timing tricker" would be for temporary use at the track and not for steady state driving?
Well the guy i bought it from was using it for drag racing in an area with no emissions rules. He did all kinds of dumb stuff to it.
Old 09-02-2016, 12:25 AM
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Originally Posted by wssix99
I was thinking to myself, "How is this possible???" I couldn't think of how this thing or circuit could fail with a constant middle-of-the-road resistance. So, I figured - let's unplug the thing and see if there are aliens chewing on the wires...

I assume the intent of this "timing tricker" would be for temporary use at the track and not for steady state driving?
This was a mod that many people tried back in the ~2002-04 time frame, if I remember correctly. SLP sold them, and most had poor results. I think most were using them full-time. Again, it was the first thing that came to mind when I read this thread, but I assumed the issue had just recently shown up for the OP.

I doubt many people are still using these though, now that top shelf custom tuning has become readily available via local or mail order sources. Best to manipulate timing within the tune rather than false sensor inputs.
Old 09-03-2016, 07:43 AM
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I would keep a hold of this tricker:
- Crack it open
- Replace the resistor with a 100 ohm one

Then, you'll have an epic prank tool or... easy way to win a drag race. Any car that has it installed will think the air temperature is 250+ degrees.
Old 09-03-2016, 11:52 AM
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Originally Posted by wssix99
I would keep a hold of this tricker:
- Crack it open
- Replace the resistor with a 100 ohm one

Then, you'll have an epic prank tool or... easy way to win a drag race. Any car that has it installed will think the air temperature is 250+ degrees.
I still don't really understand the point of the device. Why would that be good?
Old 09-03-2016, 07:27 PM
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I assume the device tricks the car in to thinking the air is cold and denser than it actually is, which would change the timing and make the car run richer than it would otherwise.


My prank would do the opposite. If pranked someone's car in to thinking the air was really hot and thin, the car would lug and lean the fuel out like a Yugo.
Old 09-04-2016, 04:01 AM
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Originally Posted by wssix99
I assume the device tricks the car in to thinking the air is cold and denser than it actually is, which would change the timing



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