B52Bombardier1
04-02-2022, 09:41 PM
Hello,
A buddy of mine in an A-body Chevelle with a mildly cammed LS1 motor has a maxxed out +25 LTFT and maybe a 4-5 STFT. I think his tune done by somebody else needs some extra fuel to get his LTFT back down to a reasonable level. That "somebody else" won't help him to make adjustments. Its +25 LTFT on both cylinder banks. Stock LS1 intake and exhaust manifolds and he's going to get me the exact specifications on his camshaft. He's running stock LS1 fuel injectors and I have a copy of his current BIN which if I remember correctly is a 12208322 and I have a good XDF for that tune. He also has a spare PCM that we can experiment with and I have plenty of others on my shelf so that we can leave his current PCM untouched. His engine idles well and starts easily and we don't believe he has a vacuum leak anywhere. His engine and transmission does not indicate any DTC codes or a check engine light.
I'm reasonably adept with Tuner Pro RT for VATS and all of the systems and DTC's that need to be killed off in a tune but I've never touched an OS to increase or decrease fueling. What tables are involved here that we should adjust to make LTFT come down to something less than +10?
Many thanks,
Rick
A buddy of mine in an A-body Chevelle with a mildly cammed LS1 motor has a maxxed out +25 LTFT and maybe a 4-5 STFT. I think his tune done by somebody else needs some extra fuel to get his LTFT back down to a reasonable level. That "somebody else" won't help him to make adjustments. Its +25 LTFT on both cylinder banks. Stock LS1 intake and exhaust manifolds and he's going to get me the exact specifications on his camshaft. He's running stock LS1 fuel injectors and I have a copy of his current BIN which if I remember correctly is a 12208322 and I have a good XDF for that tune. He also has a spare PCM that we can experiment with and I have plenty of others on my shelf so that we can leave his current PCM untouched. His engine idles well and starts easily and we don't believe he has a vacuum leak anywhere. His engine and transmission does not indicate any DTC codes or a check engine light.
I'm reasonably adept with Tuner Pro RT for VATS and all of the systems and DTC's that need to be killed off in a tune but I've never touched an OS to increase or decrease fueling. What tables are involved here that we should adjust to make LTFT come down to something less than +10?
Many thanks,
Rick