Mmcd logging problem?!?

Hello guys,

I am having a problem with my fuel trims. It shows 100% constantly, for all of them, never changes. I am getting a trouble code 31, which is the knock sensor. Obviously it's dead. Could that be the reason?
The rest of the parameters seem to be good.
What do you guys think?

So I changed the knock sensor, no fault codes anymore.
But the issue with the Fuel trims stays. All of them - 100%.

Ideas anyone?

It would help if we knew what model it was and any mods that you may have done to the vehicle. We would be shooting in the dark whether its a stock or modded non-turbo or turbo vehicle... Give us some more details and I'm sure we can give ya some ideas what to take a look at next.

I am sorry, my fault...

It's a 1G GSX '91
Running a EVO3 GT turbo, 6 bolt, Wiseco + Eagle, 2G MAF, 660cc, FMIC.
I also have just installed a AEM wideband, SAFC II and a logger.

Since I am a tuning noob, I went thru all the tech tuning threads and was just about to start with the actual tuning.

Any help will be appreciated!
Thank you in advance!

Are you pullin any fuel out with the SAFC for those bigger injectors? I would start out by pull 32% of fuel out of everypoint and that should get the car driving decent. Then use your WB and logger to fine tune the SAFC.

I'm with Silver on this one. Sounds like you need to make some adjustments to your SAFC. There's no reason those injectors should be running 100% all the time unless you have th fuel settings cranked on that thing. :2cents:

Thank's guys!

I actually set the S-AFC to -10% all the way. (-30% for the injectors and +20% for the 2G MAF).
The car runs and idles fine now. What bothers me is the fuel trims on the logger (always shows 100%) and the knock ( nothing different than 0 so far).

So, are you saying that I should be only using the WB to set all the Ne points on the S-AFC ?
11-11.5 : 1 , right?
I will make some pulls tomorrow and see if the knock will change that way...

Trims will not update until the coolant temp is 180* (or 170...carp, I forgot).

Ensure the car is properly warm before expecting the trims to update.

Trims will not update until the coolant temp is 180* (or 170...carp, I forgot).

Ensure the car is properly warm before expecting the trims to update.

Trims still don't update. I waited for the car to warm up, then cruised around to see... Nothing but 100% shows up for all the trims.

So I have no idea what's going on and how to start the actual tuning without watching the trims.

I'll appreciate any help as there are not many people who know about DSM's here :)

Things are getting even worse!
Took the car for a cruise around and... barely got back home.

This time FRO2 trims DID change - 150%, knock went to 35!!!!
Never went over 2000 rpm....