Gen II IAT sensor values. Could someone post them again?

gen 3 motorsports · May 19th, 2006, 03:42 AM

I was here same time last year asking for the IAT sensor values at various ambient temps. I ran with a fixed value resistor last summer to help quell the aggressively pig rich IAT Fuel Map the JTEC seems to have. Well, it was about 100F out today here in Portland, car did not like it at all. Ran fine this evening once the air cooled down....

Thanks in advance.

Robert
www.gen3motorsports.com

JID · May 19th, 2006, 06:35 AM

There are many who use the resistor to fix a VEC2 issue. I learned recently that this is quite bad. For a variety of reasons. Not the least of which being that the resistor makes the PCM think that the IAT is fixed at no higher than (in the case of the resistor I used ) 90 degrees. And when the air temp was actually higher than this by more than 1 or 2 degrees, the car ran like crap!

i don't have the values mapped, but i just know it wasn't a good idea...

gen 3 motorsports · May 20th, 2006, 03:55 PM

So the only real option is to have a few different VEC tunes to deal with the heat and the aggressive IAT fueling? Is there anywhere else in the engine bay/car we can locate the IAT for a more 'regulated' temp reading? Seems things are worse when you go out to the car after its been sitting in a hot parking lot for a while, or at a stop light for a long time, IAT sensor gets heat-soaked, car runs fast-ass rich. The engine coolant sensor is rock steady between 180-190F throughout these harsh heat wave conditions. Thanks for your input JID.

Robert / Portland, OR

Jack B · May 22nd, 2006, 11:27 PM

Just to give you an insight. We have logged the IAT on a Gen 1 and Gen 2 for the past two years. The cars always record much higher IAT than the actual ambient. I recently built a custom air box that is sealed to the outside, it tracks the outside ambient exactly.

I don't know if it is going to change when the temps get higher, but, this is the first year my a/f logs are always the same. I have twenty logs from the last two months and each log is virtually identical, I am starting to think the reason is that the air box is keeping the IAT at ambient, not 20 degrees higher, which it did last year.