Instructions for enabling semi-open loop

[Alex99]

Hi all,

I've searched the archives up and down but couldn't find what I was looking for.
I finished AutoVE and MAF tuning and would like to activate the O2s again to control the 14.63 cells in my commanded AFR map.
I'm using COS3.
What are the steps to do that?
What about LTFT and STFT?
I compared the tune before I started AutoVE and my current one and they differ in quite a few tables like PE, OL cold enrichment etc.
Do I change all that back to where I came from or do I just enable the O2s and thats it?

Thanks,
Alex

[joecar]

To run semi-open loop, setup for OL and set the B3647 cruise cells to the same AFR as in B3601 (i.e. set them to EQ 1.00).

[Alex99]

Ok, I did that already but I also have to enable the O2 sensors again by lowering the temperature limits to CL values, right?
Is that everything i need to do?
I will be using my MAF sensor, does this have any effect on running semi-open loop?

[joecar]

Alex,

No... keep closed loop disabled (keep the temperature limits to max); any B3647 cells that contain EQ 1.00 will run in SOL.

MAF is mutually exclusive of loop mode.


Cheers
Joe
:cheers:

[Alex99]

I'm kinda confused now.
For AutoVE I replaced the driver-side NBO2 with the LM1 WBO2. The pass. side NBO2 is still in place and connected.
My fuel map has a lot of 14.63 cells, so according to what you said, this would mean that during my AutoVE process the STFT works at least on the pass.side O2 and tries to correct any variances when AFR is commanded 14.63 e.g @ idle.
By judging my LM1, I am not at a stable 14.63 at idle but it fluctuated quite a bit in the tuning process so I doubt it was getting controlled by STFT.
I haven't logged those to check for activity though, so I will do that in the next days.

Why do we set the temp. threshold for CL anyways to the max if they still work anyways?

I'll send you a recent tune so maybe you can have a look and tell me if my settings would qualify for semi-open loop.

Thanks Alex

[joecar]

CL uses the NBO2 sensors to calculate the trim (LTFT) to apply to fueling to maintain stoichiometric AFR; the trim (LTFT) is derived in two stages (STFT and LTFT).

OL ignores the NBO2 sensors and does not trim.

Semi-Open Loop (SOL) is not CL... it is OL with the additional feature of trimming (STFT) on stoichiometric cells in B3647... this is a feature of the COS's; a non-COS that has B4206 defined and enabled can also do this.

Yes your tune file is set for OL and your B3647 has 2 areas set for SOL.

Is your LM-1's other channel simulating NBO2...?

Don't do AutoVE with B3647 set to SOL... unless you filter out SOL data from your log.

[Alex99]

Joe,
thanks for the insight. I was not aware of this fact.
No I don't use the channel simulation with my LM1. I also don't plan to keep the WBO2 in the car.
I did indeed used the VE map with those areas set to 14.63 for my AutoVE tuning. I guess this messed it up a bit?
Should I just change it to 14.7 and AutoVE again?
Then I will tune the MAF again and after that I will pull the WBO2 and put the original NBO2 in and should be fine.
When I put the NBO2 back in, I would change those areas with 14.7 back to 14.63 and should be in SOL then, right?
Other than that, I don't have to do any other changes in my tune?
I want to activate DFCO agin when I'm done. This should have no effect on SOL, right?
Can you confirm this procedure?
Alex

[joecar]

Yes, set it to 14.7 and redo AutoVE.

When all done doing AutoVE you can run SOL (I'm wondering if this is a bad acronym... ;)).

DFCO only activates on deccel, so you should be fine.

[Alex99]

Hi Joe,

I redid all the AutoVE and have now put the 14.7 cell back to 14.63 to enable SOL.
Today I was logging the STFT Pids and they were all at 0 and didn't change.
I have enabled the STFT in idle but I haven't seen any changes.

The AFR in b3601 is set at 14.63 (14.628...)

Is there anything that I missed or anything different that I should log.

Right now I have still the WBO2 in the driver side exhaust and only the pass. side NBO2 installed. Could that be the reason for no activity?
I want to put the driver side NBO2 in but then I can't double check with the WBO2.

Thanks
Alex

[joecar]

To do SOL you need pre-cat NBO's (or wideband NBO mode) on both banks.

What wideband do you have...?

[Alex99]

Both bungs are the stock pre cat locations. One has the original NBO and in the other I have the Innovate LM1 WBO.
I don't simulate the NBO with the WBO.
Do I have to set any MILs or so when I put in the other original NBO?
Why wouldn't it work with just one NBO? Because it senses that one circuit is open?

[joecar]

One bank might or might not work... but the other bank would just stay OL and STFT would flatline at zero (which is what you're seeing).

[Alex99]

I'll put in the second NBO and will log again. If this still doesn't work, is there anything that could cause that then?

[Alex99]

For the record,
after plugging in the second NBO the STFTs work just fine.
Thanks,
Alex

[joecar]

Alex, thanks for posting your results. :cheers:

[stigmundfreud]

Hi Joe, running non-cos here, to get SOL do I need to disable CL (from what I am reading) as if doing AutoVE. Turn off LTFT, enable 4206 and then rely on 4206 to keep stoich on cells in 3605 set to 14.63 and ignore stft at other times?

[joecar]

Mike,

that is correct... altho I don't know if it works on all OS's that have B4206;

(your B3601 contains 14.63, right...? some OS's have B3601 set to 14.68).

Joe

[stigmundfreud]

yeah 14.63, I've got a chance to check a few tunes out on the rollers in a few weeks, so going to test both with some learnt ltft then run it in semi open (just enable stft in OL and put CL temp to max). Should be ok with maf feed back and am I correct in assuming it works at STFT for stoich and just OL for all other cells? I forgot so much in the months since doing it ;)

BTW /hitting CA/NV/UT/S.CA in a few weeks I owe you a beer ;)

[joecar]

STFT/SOL only for stoich cells... other cells will be OL.

[stigmundfreud]

sweet!

[stigmundfreud]

quick thouht, as I am now running the maf its ok to run dual spark tables?

[joecar]

HO/LO tables are good to run in case you get knock...

Actually, might be a very good idea with the MAF in case it gets fouled (in which case it under-reports which causes timing to be in the low-load range which may be sufficiently high to induce knock at the actual load).

[stigmundfreud]

cheers joe (surprised you didnt say uncouple the MAF and just be done with it ;))

[joecar]

Well, I would... but...

I've found that some features get disabled when the MAF is failed (e.g. like misfire detection, shift/pressure adaption, and possibly a few others that I haven't oberved yet...)...

Now, some models come from the factory without a MAF...

I'm thinking there must be some other way to disable the MAF without failing it.

[stigmundfreud]

Well, I would... but...

I've found that some features get disabled when the MAF is failed (e.g. like misfire detection, shift/pressure adaption, and possibly a few others that I haven't oberved yet...)...

Now, some models come from the factory without a MAF...

I'm thinking there must be some other way to disable the MAF without failing it.

thought I had read you could zero 5001 instead of failing it

[joecar]

thought I had read you could zero 5001 instead of failing itI'll have to try this.

[stigmundfreud]

I'll have to try this.

it was a tip to avoid having to disconnect the maf, works well if you have the 5 wire connector.