fuel trims never move

[moonstation2000]

does anyone know what would make my fuel trims stay stuck at 100, 100 & 100?
i've changed my ecu and my mas but nothing changes the fuel trims. i need to know what would block the trims from changing. btw, my o2 trims move normally, as well as o2 sensor readings. any help would be greatly appreciated.

 

[nined2tsi]

Hey I have the same problem and looks like you got as much help as I did. Nothing

 

[kpt4321]

I'll ignore the fact that sissypants here wants me to clap my hands and fix everything instantly.

There are a couple reasons for the fuel trims not to move; if your tuning was perfect, they would stay at 100%. That will never happen though, since they tend to move a little bit from day to day anyway.

If you simply don't give them enough time, they will not move. How long have you been watching them?

The trims will not work if the car is in limp mode, due to something like a check engine light.

 

[WhiteTsiAwd]

Wow, theres more then just me with this problem.

But i know what my problem is FINALLY! I have a CEL because of my O2 sensor, i think. It shows up as a O2 sensor when i run the CEL. So hopefully its that.

I also have a EGR Block off plate so hopefully that isnt whats causing the CEL aswell. I dont think it is because it dont show up.

KPT4321, why would the trims not work due to a CEL?

 

[steve]

Since the O2 sensor isn't working the ECU never enters closed loop and the trims never get updated. A bad temp sensor will also keep the car from entering closed loop.

Steve

 

[WhiteTsiAwd]

Could this be a reason for my car running rather crappy top end? Quite a bit of knock...

 

[moonstation2000]

I've been watching them for 1.5 years - since i got my pocketlogger. i didn't know about a cel causing them to lock at 100. i throw a bps code from time to time, the light goes on and off. i'l have to check that out on my ride home.
i'll post again as soon as i have some results

 

[WTNGST]

I've been watching them for 1.5 years - since i got my pocketlogger. i didn't know about a cel causing them to lock at 100. i throw a bps code from time to time, the light goes on and off. i'l have to check that out on my ride home.
i'll post again as soon as i have some results

I logged a guys car two weeks ago with the same problem. O2 voltage and O2 trim looked normal but fuel trims didn't move. The car ran horrible. He did mention he had done the block off plate. He had just bought this car and didn't know the history.

 

[moonstation2000]

i just installed a 2g mas and 550's and now my fuel trims move. in the past i have changed both ecu's and mas's in an attempt to isolate the problem, nothing worked.
could the 2g mas have fixed something for me? the ones i tried previously were 1g mas's.

 

[steveVR4]

could the 2g mas have fixed something for me? the ones i tried previously were 1g mas's.

A bad mas would probably cause you to go into limp mode. Maybe all the other 1g mas's you tried were bad??

 

[moonstation2000]

actually, my fuel trims moved from 100,100 & 100 to 81, 92 & 101 but they are as stuck at those new numbers as they were at the old ones. I can see from the o2 trim that i am running rich and the computer is frozen and unable to compensate with the trims.