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02:47:18 - 12/29/2024
Dakota Performance
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Reapist
Gen I
 
8/31/2007
11:17:19
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 Subject: IAT Sensor Relocation
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Message:
My IAT sensor is in the #2 intake runner. Everything I read syas this gives a false reading and if I relocate it the fuel mixture and timing will be optimised. Now, I'm instructed to relocate it into the intake tube for the iar box. I do not have one.
I have a 94 Dakota with a K&N airbox which really is nothing more than an open element with a chrome top and bottom. I thought of drilling a hole in the bottom breather pan and installing it there bit it also gets a lot of heat.
So, I've been pondering this a few days and here are my thoughts on the subject: What we really want to measure is the ambien air temperature that the engine is drawing on. Why can I not find a more suitable location, such as the fire wall to mount the sensor on. Does it really need air passing over it or will it be adequate to let it soak in the ambient air under the hood?
Thoughts?
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Marv
Dodge Dakota
JOIN HERE
8/31/2007
23:09:49
| RE: IAT Sensor Relocation
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Message:
The air temp of the intake air is best measured close to the engine, not far away from it.
Reason is, it's a better indication of the true temp of the air that's getting pulled into the cylinders, because the air gets heated by the manifold as it flows down the intake runners.
To give you an example, I have a Scangauge (www.scangauge.com) attached to my diagnostics port, and two of the parameters I watch all the time are coolant temp and intake air temp. My IAT sensor is in intake runner #5 (4.7L), and at highway speeds, the air temp at the sensor is never less than 20 degrees above ambient. In stop-and-go traffic, it routinely gets over 100 degrees above ambient. No "cold air intake" system can overcome that heat transfer that occurs between the intake manifold to the incoming air charge(I've tried several).
Moving the IAT sensor farther away from the engine, into colder air, "tricks" the computer into thinking the air going into the cylinders is colder than it really is. This does have a benefit: the computer adds a bit more fuel, which richens the mixture giving a bit more power.
However, the upstream O2 sensor still has control over air/fuel mixture based on the amount of oxygen in the exhaust stream, so the richer mixture is often corrected by the sensor.
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Kowalski
GenIII
9/01/2007
09:32:25
| RE: IAT Sensor Relocation
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Message:
While I've read what Marv says; and that moving the IAT can trick the sensor into a lower reading, causing an increase in fuel - I've never read that the stock location gives a false reading. As Marv explains, it should give a pretty good reading of the air going into the cylinder where it will meet the fuel required. Feeding your truck cold air would be a better mod, rather than trying to fool it into thinking it's getting cold air.
Lead, follow, or get out of the way
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