VE's are good, runs fine in OL, trims WAY too much fuel in CL, even with new O2's

[rumblebox]

it's safe to say that i'm completely stumped as to why my 6.0 runs fine when going straight off the VE tables, but goes stupidly lean as soon as it goes into CL. i've replaced the O2's too just to make sure they werent cooked. so for a while now, i've just been running with disabled trims.

and by lean, i mean popping with more than half throttle. the only way i can make it run right in CL is to manually command AFR to 11.5:1 with EFI live.

the O2 wiring has never been modified. so i'm pretty sure there's no way they're switched with each other.

[jeast]

Try disabling ur MAF and just run SD. Im no pro, maybe u already tried that.

[rumblebox]

Try disabling ur MAF and just run SD. Im no pro, maybe u already tried that.

I've actually been running it in SD for a while.

[jeast]

So if it runs fine in SD just keep it there. U must have an issue with ur MAF. Im kinda new to tuning, but i'm only running in sd mode now. I actually took the MAF out all together. Since im setting up my trubo, the MAF would only be good for low boost. Most guys r just running SD.

[rumblebox]

The MAF is irrelevant. My issue is excessive fuel trimming in closed loop, and having to run open loop for it to run right.

[jeast]

I'm sure the boys at Nelson can sort it out for u. I'd start looking at ur temperature sensors, if they r reading accurately then it's gotta be in the fuel compensation amounts in the tune. Fuel amounts change depending on IATs and ECTs.

[rumblebox]

I'm sure the boys at Nelson can sort it out for u. I'd start looking at ur temperature sensors, if they r reading accurately then it's gotta be in the fuel compensation amounts in the tune. Fuel amounts change depending on IATs and ECTs.

Those are accurate too. It's actually trimming over 25% at times.

[EmmerichLSx]

Have you looked into a vacuum leak? Seems like if you can run it in OL SD just fine then have issues in CL, the O2's are seeing fresh air when they shouldn't be.

[rumblebox]

Have you looked into a vacuum leak?

I considered that, but it think it would be doing the opposite with a vacuum leak. Running lean in OL and adding fuel with the O2's on.

[EmmerichLSx]

I considered that, but it think it would be doing the opposite with a vacuum leak. Running lean in OL and adding fuel with the O2's on.

Yeah that makes sense. Wouldn't hurt to go get a smoke test if you can't figure it out soon.