**I know I am beating a dead horse, just looking for advice to try**

Been fighting the slow heating on o2's after new setup install(TVS 5.3 + 4L80e). I have 1 7/8 with true dual 3" dumped pre axle, so they do not heat up nearly quick enough. They only really switch as they should when highway driving. What are my options? Header wrap the long tubes, mess with proportional idle tables, lower idle timing?? Who all is using solely OLSD tune, and have you had any adverse side effects?

My logs until full warmed up are all over the map. Took out tonight after about a 10min drive a few minutes earlier, and the STFT's went all over and truck nearly died trying to drive at 10.1 AFR. Disabled the LTFT's to try to see if it aided with symptoms, but pretty much runs like a$$ until it is cruising at higher speeds or heavy throttle. Just feels bogged down.

Cam/Mods in sig. Attached a quick scan. Any of your experts want to chime in and help a brother out? I have searched, a lot.... basically been reading every thread I can for a month straight.

 

Post the tune if you want some good advice.

The logs show the following:

1. o2's are not oscillating like they are supposed to be.
2. Trims are fked up. (yes, that is a professional answer)

I tried OLSD once. I never did it again. For me, using STFTs and disabling LTFTs provided the most stability

 

Yes, trims are jacked on start up for about 5min. If I get onto highway, the o2's start switching and trims are within 5. Very odd.

Here is current tune

 

So,

Please don't take this the wrong way,

Put it back in closed loop.

The #1 problem with open-loop is that you're telling the PCM, you're right, it's wrong. It takes out any correction abilities that the PCM may have or want to do.

Open-loop definitely has it's place but for what you're doing, closed-loop with LTFTs disabled makes much more sense.

 

It has closed loop with the LTFT's disabled, that is the current setup.

I have not setup anything for open loop only, as I wanted to solicit feedback prior to doing so.

 

Your o2 switching issue is due to the temp specified in the Closed Loop Enable table.

Bring that down to 130 and see if they don't start behaving better.

Look at it this way, with the current temp, if it takes 5min to get to 180 degrees, then there is your 5min.

I would also change the Rich/Lean vs Airflow to reflect 450 (or 451, matter of preference really) across the board, retune the VE table and go from there.

 

Interesting note, I will possibly try the closed loop enabled change and see if that changes anything. On the initial file, they were at 131*, and the most recent changes seem to have made it worse. That being said, even when the ECT is sitting at 200* and I restart the truck, it takes at least a couple min to start acting right.

On the Rich/Lean vs Airflow, I believe they stated they modified that to keep the pcm from thinking it was lean and adding fuel. If the closed loop enabled change doesn't help, I will modify that back to 451 as before.

Here is a file cruising at highway speeds omw home from the shop... shows the difference from the original start up. Clearly very different looks on the log.

Any other ideas/suggestions? Going to keep trying to hunt this down or try out OL if all else fails...

 

If the VE table is tuned properly, any stagnation in the O2's in low airflow conditions will swing just a few percent in each direction. Turning on the O2s sooner does not always help if they are not hot enough to function properly. You can command a different AFR in idle conditions to prevent open loop while in idle. The rough running after start when hot is likely from error in your VE table since the O2s are initially ignored. Retarded timing will can result in hotter EGTs.

 

Thanks for the info. What table are you referring to for the OL AFR?

I have tried modifying the B1 and B2 Rich/Lean tables, it runs better with the lean condition down around 400, because the O2's wont oscillate until I get to highway speeds. Also, the o2's have 14ga wiring ran directly to them now to verify the get the voltage they need, still flatline until driving for several minutes. After the first several minutes (regardless of ECT), then it starts to smooth out and the STFT's adjust accordingly.

Anyone running in solely OL want to chime in here? Looking at my logs, it appears as though the VE table will need to be adjusted in order to have any drivability... At this point, I just want to be able to get into the truck and drive.