Engine power surge.
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Teching In
Joined: Feb 2014
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Engine power surge. Hi i couldnt find my exact issue so forgive me if theres another one out there but i have an 08 GMC sierra 1500 with the 5.3 regular gas. Im having this odd issue where if i maintain throttle position climbing a hill it feals like enginge power drops a bit and picks back up and just does it the whole way uo the hill. It won't do it when i accelerate harder but ive noticed it happens when downhilling when i shift down. It idles fine and runs great. Ive just replaced all 4 02 sensors as they were throwing codes but that didn't change it. Other than that the engin is stock and has a Diablo tune and 80000 on it. I have read things about a dirty throttle body but idk know for sure and if i cleaned it is there a way to do the idle relearn with a Diablo trinity. Any help would be greatly appreciated.
Thread Starter
Teching In
Joined: Feb 2014
Posts: 15
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Only mods are straight pipes K&N intake (which i clean the MAF sensor often) its lifted sitting on 36's. The Diablo Trinity has been used and updated since 2 years ago. I use it for the extra power. Its an 08 5.3 with VVT and AFM which is the same thing as DOD but i turned it off with the Diablo programmer.
Last edited by 65lsk10; Oct 9, 2016 at 12:38 AM.
Thread Starter
Teching In
Joined: Feb 2014
Posts: 15
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I know DOD is off i checked it in the tune and you would definitely notice with my exhaust setup. The Diablo modifies the fuel maps and ignition timing as well as shift points and pressures for the transmission as well as some other neat stuff. Im debating on pulling the tune out and updating the Diablo and installing a fresh tune as this seemed to start happening with the tune. Im thinking maybe the computer has made a learn change and putting the OE one back in would remove the change and putting the new tune in would start from the OE one.
Thread Starter
Teching In
Joined: Feb 2014
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still no fix This is driving me nuts... There are no codes being thrown but it never used to do it and i feel it shouldn't. I changed the MAP sensor and that didn't change anything. I read it could be the TCC, But it does it in Tow haul and if you're downhilling in second... Could it be the throttle body? I really don't want to go throwing parts at it.
