PieRat

Hi guys, i was going to look at some boost readings today but i noticed that my fuel trims were really off -12.5% and -11%..i was like wtf then noticed when i applied throttle aka not idling or cruising the long terms went to basically 0. As soon as i let off back to 12.5 and 11... i never noticed them 2ver changing dynamically before theyd always be static and poll over log periods. And no i am not checking short term its definteily LTFT..

im going to take a bottle of brake cleaner and make sure no intake leak..

PieRat

Can of brake cleaner used, no leak evident. Confirmed when I go from -12.5 to -1.6 and -11 to -0.8 which would be what I'd usually expect to see. The fuel trims don't change when revving in park but when in drive and you give it over a certain % throttle it changes. I'm assuming its changing when I switch from the open loop to closed loop.... Anyone experienced this before? I did just retune the car a few weeks back maybe its related..

503C43 ////AMG

negative fuel trims mean you are running rich, not lean. If your LTFT's were +12.5 then I'd be looking for a vacuum leak.

PieRat

Yeah good point mate. I think this is just some buzzy tune related stuff im more confused about ltft changing so vastly in real time..

C32owner

Interesting, I also had some new mods added recently and needed a Retune which is done and for the first time my LTFT where also out of whack as you describe with -12% ie running super rich and fuel being taken out.. I am not wondering if the latest torque app update has been changed and the readings on the app has been modified for showing these drastically different numbers... I was never more than - 4% before and it was super stable... Now the LTFT needles are jumping all over the place.. I'm thinking it's the latest version of the app that may be out of whack... Idk

ItalianJoe1

The car doesn't have one fixed LTFT value for every operating range. It is moving from low rpm/load ranges to more medium range cells and isn't needing the adjustment.

05-E55

I've been using Torque app to look at various info, but I have no idea what "normal" numbers should be. Can you guys post some of your logs for me to compare to please? I look at intake temp, timing, fuel trim, boost, just about everything that's available.