Engine dies when iat plugged in!!!
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Engine dies when iat plugged in!!! This is a 99 Camaro that went from a v6 to an lq9. We bought a used harness for a 99 LS1 camaro.
What could cause this issue? I check the wires back to the computer and they seemed fine. I even cut them and spliced the iat four inches after the cpu. Same symptom. It reads about 230 degrees when plugged in, koeo. With it unplugged it reds 120 deg. steady. When I apply heat to the sensor the temp reading drops and with cold air the reading goes up!!
This is all with a new sensor. HELP!!!
What could cause this issue? I check the wires back to the computer and they seemed fine. I even cut them and spliced the iat four inches after the cpu. Same symptom. It reads about 230 degrees when plugged in, koeo. With it unplugged it reds 120 deg. steady. When I apply heat to the sensor the temp reading drops and with cold air the reading goes up!!
This is all with a new sensor. HELP!!!
Last edited by revolutionmusclecars; Sep 4, 2014 at 02:52 PM.
IAT is just a dumb resistor. Why it reads backwards,
is an interesting question.
I think you should begin with measuring the IAT pin-pin
resistance (DMM) at a couple of known temperatures
(like, say, outside air and ice-water) and compare those
to the proper sensor reading for a LS1 IAT, per the spec
table in the Helm manuals. If you're roughly right for the
numbers and their slope vs temp, call it good and look
elsewhere.
Verify that your low reference looks like GND and the
high side is in range (1V < V(IAT) < 4V, I expect).
Swap another IAT sensor into your present problem
vehicle, and swap this IAT into a known normal vehicle
and read it there.
One or all of these ought to point you closer to the
problem.
is an interesting question.
I think you should begin with measuring the IAT pin-pin
resistance (DMM) at a couple of known temperatures
(like, say, outside air and ice-water) and compare those
to the proper sensor reading for a LS1 IAT, per the spec
table in the Helm manuals. If you're roughly right for the
numbers and their slope vs temp, call it good and look
elsewhere.
Verify that your low reference looks like GND and the
high side is in range (1V < V(IAT) < 4V, I expect).
Swap another IAT sensor into your present problem
vehicle, and swap this IAT into a known normal vehicle
and read it there.
One or all of these ought to point you closer to the
problem.
Thread Starter
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Joined: Mar 2014
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Jimmyblue I'll try that and report back.
Marc It's a computer from a 99 Camaro LS1 flashed with all the info I gave the tuner for this car.
To add on to this, I tried plugging it in after "tricking" the scanner to read 90deg IAT and it still died
Marc It's a computer from a 99 Camaro LS1 flashed with all the info I gave the tuner for this car.
To add on to this, I tried plugging it in after "tricking" the scanner to read 90deg IAT and it still died
