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Tuned without Iat connected

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Old Apr 25, 2022 | 02:45 AM
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Default Tuned without Iat connected

Hi

I recently got my LS1 rebuilt and tuned straight after. I got decent numbers from the tuner and after a few weeks noticed the IAT sensor was unplugged. I've since plugged it back in.

I have a maffless tune and wondered how the tune occurred with an IAT sensor connected. Will this work as expected now that the IAT is connected or would it now need to be retuned? I didn't notice any difference in power or fuel economy since its been reconnected.

Any insight would be greatly appreciated
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Old Apr 25, 2022 | 03:30 AM
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You need to check the fuel trims.

IAT disconnected reads -40F which causes a rich condition.

If it was tuned around that, the tune will be very lean when the IAT is reconnected.
The trims will be adding fuel.

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Old Apr 26, 2022 | 07:18 AM
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Agreed Ron. And surprising the tuner said nothing??
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Old Apr 26, 2022 | 09:35 AM
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Originally Posted by Darth_V8r
Agreed Ron. And surprising the tuner said nothing??
Not surprising, I've watched a few well known tunas repeatedly blowup cars with glaring issues. Some even send the same tune to multiple people with different setups, its amazing really but the majority of people have no idea.
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Old Apr 26, 2022 | 04:08 PM
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Originally Posted by SLOW SEDAN
Not surprising, I've watched a few well known tunas repeatedly blowup cars with glaring issues. Some even send the same tune to multiple people with different setups, its amazing really but the majority of people have no idea.
There's a word for that...'reputable'.
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Old Apr 27, 2022 | 01:09 AM
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Yea didn't hear a word from them about it. Car seems to run fine otherwise. I went for a drive approx 20mins and these were the results. No long term fuel trim has shown. Unsure if it requires longer driving but thought a baseline was recorded.
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Old Apr 27, 2022 | 07:49 PM
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Went for a 20min drive. Appears to have no Long Term fuel trims and the short terms are all over the place. Not sure if this is expected
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Old Apr 28, 2022 | 11:22 AM
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Originally Posted by Aussie81
Went for a 20min drive. Appears to have no Long Term fuel trims and the short terms are all over the place. Not sure if this is expected
I've definitely seen worse..
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Old Apr 28, 2022 | 03:37 PM
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LTFT is turned off. No big deal.
STFT will look like that, not sure what you are measuring with?
But they are centered around 0. Which is good.
Is the IAT reading temp now? if so, unplug it again and see what the trims do.
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Old Apr 28, 2022 | 11:18 PM
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Intake temp stayed constant at 33 degrees celcius (91 Fahrenheit). Surprised it stayed at that temp during a 20min trip. I did unplug it while it was running and it didn't update to - 40 or change at all but wasn't sure if this was a safety measure. The car is in the workshop so can't switch it on unplugged to see what happens. I'm just using a Bluetooth obd2 scanner.
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