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Anyone else with a 408 have problems

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Old Oct 5, 2008 | 02:06 AM
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Default Anyone else with a 408 have problems

Since installing the 408 LQ9 my cars IAT reads 150+ after driving for 10 mins. Do yall have the same problem, I have read the IAT relocation mods, but I dont want to relocate it due to thats the air temp going into the intake. What have yall done to fix this problem, is relocating the IAT the only fix, and if i relocate it do i need to tune the car not to go off the IAT (hp tuners)
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Old Oct 5, 2008 | 01:30 PM
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From: plano
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i dont know why your IAT is running hot............. my doesnt but i have the 85mm z06 maf so i am not sure but when i had the stock maf and lid it ran fine and it wasnt relocated.... you might have a bad sensor or some other issue
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Old Oct 5, 2008 | 02:22 PM
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Wow that is crazy hot. I have mine in the stock location (in the lid) and I may see the temp go around 91 at idle on a hot day. What is the ECT at and is the front air deflector installed and not hanging down?
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Old Oct 5, 2008 | 02:37 PM
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Here is my setup



Before I installed the 4" Cowl hood it Idle driving down the road the IAT would get as low as 120. Idle it would jump to 150 quick. After installing the hood, driving down the road it averages 90 and at idle, it will slowly go up to 150 (which is the max HP tuners shows)

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Old Oct 5, 2008 | 02:44 PM
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If you're using a 85mm MAF try and switch the IAT to the MAF. This may yield better results. That intake looks like a giant oven prone to heat soak. Does the IAT go down once you're cruising at highway speed?
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Old Oct 5, 2008 | 02:58 PM
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Yes, it goes back down. I have the BBK 85mm intake. I dont think I know how to switch it to the maf?
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Old Oct 5, 2008 | 02:58 PM
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I don't have a 408, still stock 346 LS1.. But since i swapped my cam in 2006, my IATs are whacked too. What i mean is that i have not hot start with my cam. As soon as my car runs for about 5 mins and the coolant gets warm, you go to shut the car off, start the car again and the cam can not find idle at all for about 5 secsonds... But all i do when starting the car is hold the idle at about 1200 RPMs for about 3 seconds and it idles fine.

But i guess what i am saying is if you dfind out why your IATs are off let me know
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Old Oct 5, 2008 | 03:05 PM
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Originally Posted by cryptnosis
Yes, it goes back down. I have the BBK 85mm intake. I dont think I know how to switch it to the maf?
How much does it go down? The GM 85mm MAF comes with an IAT already installed including a plug. You can use it by plugging it in to the stock harness.
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Old Oct 5, 2008 | 03:43 PM
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Someone else has already asked, but what is your coolant temperature?
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Old Oct 5, 2008 | 03:48 PM
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I have a thunder racing (red colored) maf, didnt see anyspot for the IAT connections
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Old Oct 5, 2008 | 03:51 PM
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coolant temp not sure, I have a 160 degree stat my car reads 170 inside (the bottom left indication)
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