Fuel Trims not moving

[BstNside]

I have a pocketlogger, SAFC, BIG16g, stock injectors, and Hacked Mass Air. My O2 sensor is fine (metered it at 12ohms). None of the Fuel Trims Low,Mid, or High are moving, they all are at 100. The o2 trim moves and fluctuates, but none of the others.

What is going on?

91 AWD 5spd

 

[92redman]

They are supposed to be at 100 if your 02 is consistantly where your ECU thinks it should be. Remember that the fuel trims on the 1g's are long term and only affected if the ecu notices a trend in adding or removing fuel.

 

[BstNside]

So my SAFC settings are exactly correct? I can't believe that. My o2 trim is all over the place, I understand that it is short term and will change faster, but Low, Mid, and High are all at 100 not 99 or 101. I find that hard to believe.

 

[adam355]

How does the car run?

 

[steve]

Check your Engine coolant temp, if it reads too cold the ECU doesn't update the trims.

Steve

 

[WhiteTsiAwd]

Sorry to high jack your post but whats the Ideal Coolant Temp. for the ecu to keep the trims moving?

 

[steve]

I haven't look at that code in a couple of weeks but it should be over 176F or something like that. But you do need to have a working O2 sensor pluged in for the engine to ever go into closed loop. And if your not in closed loop fuel trims aren't updated or used.

Steve

On my car the trims don't start to update until I hit 190F.

 

[BstNside]

I do have a working O2, I haven't checked the coolant temp on the pocketlogger, but the gauge on the dash works fine.

The car runs decent. It has alot of part throttle knock (when I am cruising) and bucking at low RPMs in 3rd, 4th and 5th gear. I am trying to get it more driveable, that is why I posted. I am guessing that the trims not moving has something to do with the habitual bucking and knock.

Thanks

 

[steve]

I do have a working O2, I haven't checked the coolant temp on the pocketlogger, but the gauge on the dash works fine.

The O2 comment was directed to my friend WhiteTsiAwd.

The temp sensor for the gauge is not the same sensor the ECU gets it's colant temp from. You'll have to check with the logger. A bad ECT sensor should cause a CEL but I don't know how far gone it has to be before it triggers it.

Steve

 

[BstNside]

The O2 was just to affirm that I have checked it, I will check the coolant temp on the logger. Do you know what the minimum temp has to be?

Thanks

 

[WhiteTsiAwd]

Even when I had my O2 plugged in, my fuel trims never moved. So it really would not matter if it was plugged in right now, would it? Since it dont work anyways.

Once again, sorry to high jack your post!

 

[steve]

I see it slightly different. It's never going to work with the O2 unplugged. Plus your car will run pig rich all the time with it disconnected, richer than it does with a failing one.

Now back to our scheduled thread.

Steve

 

[BstNside]

I checked the ECT on the Logger, it is always above 185 and gets up to 205. Any other ideas?

Thanks.