question about fuel trims and wideband reading

[coryf1233]

On my logger I have lean fuel trims
on my wideband at idle its at 18, cruising around it fluctuates between 14-16 and then at wot its around 11.7

Can someone shed some light on these numbers and let me know what to do..

I have searched!!!

 

[the_mork]

WOT should really be a little bit richer, you should be aiming for around 11.1-11.5

A fuel trim of 18 is the ecu adding fuel in order to maintain a stoich condition for better fuel mileage and emissions. The fluctuation from 14-16 is normal, it is your o2 feedback loop moving around to try and maintain 14.7 AFR the fluctuation means you're in closed loop.

 

[-red97rum-]

On my logger I have lean fuel trims
on my wideband at idle its at 18, cruising around it fluctuates between 14-16 and then at wot its around 11.7

Can someone shed some light on these numbers and let me know what to do..

I have searched!!!

Check for vacuum leaks, especially if you're running lean at idle. Something similar happened to me a while back and I had a decent vacuum leak from my type s bov. Low fuel trim was at 139% when it had been at 104% the day before. Try testing for boost leaks. I would run rich at wot because my vacuum leak at idle turned into a boost leak at wot. I have the fuel mods to handle the extra boost though.

What turbo are you running and how much boost? What fuel mods do you have? I see you have a full exhaust and a hacked air can. If you've turned up the boost with a stock fuel system, free flowing exhaust and less restrictive intake it would not be unusual to see a lean condition at wot. Are you logging any knock? What's your timing look like in your logs? Where in the exhaust stream do you have your wideband sensor?

 

[coryf1233]

I am at stock boost still, no boost controller
I have my wideband sensor right below the flex pipe
timing is about 7 degrees at idle at wot i am not sure, ill have to get one of my logs on here again
I have no knock all the way to 6500
also it is a stock fuel system.should i get a fpr to contrl things?

 

[coryf1233]

I know i have exhaust leaks so is it possible that its throwing my readings off, and with the numbers that im getting is this going to cause a lot of damage..

i leave for school on friday and i wont have money to do anything for a while thats why i ask

 

[coryf1233]

And is it normal for fuel trims to stay stagnant throughout the log?

 

[the_mork]

long term fuel trims yes, short term trims no.

 

[coryf1233]

ok well i just did another run, i apologize i cannot get it on here right now..

at wot my wideband is reading rich( below 11)

but my fuel trims speak otherwise, they are all above 100% however my low fuel trim was at 199%?????

and my o2 voltage doesnt seem to be stable at all, its dipping and rising all over the place

and for the most part my fuel trims are locked where they are at, maybe fluctuating a little bit