I logged my cold start and my fuel trims show the short fuel trims being -11.7% and the long are -1.3%, I am unsure what to adjust in the tune to get this to run better in Open Loop, once the truck hits closed loop it runs perfect
I logged my cold start and my fuel trims show the short fuel trims being -11.7% and the long are -1.3%, I am unsure what to adjust in the tune to get this to run better in Open Loop, once the truck hits closed loop it runs perfect
EFI specialist
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I?ll post my tune and log when I get home from work today
Are you trying to fix a problem or chasing numbers?
Both those trims are completely reasonable as a snap shot. It will never be 0/0
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Originally Posted by Alvin
It idles bad in open loop, like if I put in gear while in open loop it will die, runs perfect once in closed loop but open loop if you put in gear or hit the throttle when it tries to come back to idle it will die or bog down and catch itself
Data log and tune file......
EFI specialist
Advanced diagnostics, tuning, emissions
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truck tune 1.hpt
log #1.hpl
i did a log on the cold start, it barely wanted to start had to give it a little throttle just to get it to start, about 27 degrees with wind at the moment here
additional info
5.3 lm7 flat top pistons, btr stage 3 cam and springs, jegs sheetmetal intake, headers, 80lb SEP 850cc injectors EV1,
truck was tuned by a local shop, runs good when warmed up, cold starts are horrible, im attaching a additional log file you will see once warmed up if i rev the engine will almost catch itself it seems, when returning to a idle it idles down before smoothening out.
log 2.hpl
Injectors are junk. The data isn't right. The trims stop around -6% LT and -1.5% ST and the narrowbands are still over 900mv. The thing is practically choking on fuel.
EFI specialist
Advanced diagnostics, tuning, emissions
HPtuners dealer and tech support
email=[email protected]
So bring the fuel down? I?m very new to this tuning, I got it because I?m not pleased with the shop I went to and not others around so I figured I?d attempt to learn this just an unsure the direction I can see on the data and smell its pig rich of fuel I just am looking for what adjustments would need to be made to bring that into correction? Thanks
No. Run it with the correct injector data like the attached. Don't forget Transients tab.
Why are you running 128lb injectors on an NA build?
Lol who tuned this trash? There are all kinds of problems.
Last edited by SiriusC1024; 01-11-2024 at 08:35 PM.
local shop tuned it, i havent touched anything yet, and when i mentioned i thought it was running off they quit getting back to me, thats why i got the mpvi3 and decided to be done with the shop
also the injectors are 80lb i have no idea why he has 128 in there, so change that to 80 as well?
Here man. Start with this. They didn't fail the MAF correctly, spark too high, no spark retard when knock detected, etc etc.
Edit>View Change/History Logs (Ctrl+L)
What all mods are done to the vehicle? Also, why the 128lb injectors? Are you planning boost?
Do you have the injector data file?
it only has 80 pound injectors in it, im unsure why he put 128 pound in there, truck is 5.3 flat tops, btr stage 3, headers, jegs sheetmetal intake,
no i unfortunately dont, i know they are SEP 80lb 850cc deka style injectors
Cam or anything?
btr stage 3 truck cam
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