Going MAFLESS and O2 less

[The Alchemist]

hey people a question:
though I'd have a look at the virtual VE table and see how close it was and have a play basically so I set up the MAF fail limit to "0" as per LS1 procedure then I went into O2 trim and put the losed loop temp enable up to 140 deg and LTFT enable up to 140 degrees and reflashed the PCM. Diasabled the MIL etc.
When I started up the engine it ran fine but the fuel trims both STFT and LTFT were still trimming away happiliy as if they had never been turned off.

What have I done wrong?

Mike

[The Alchemist]

bump......no suggestions...

[Chalky]

Is that 140 C or 140 F? Sounds like you are still in CL!

[The Alchemist]

140 C

[carneb]

The Description for {B4206} says:


When disabled, the PCM will always use
- {B3605} Commanded Fuel When in Open Loop (Normal) or
- {B3647} (not available in this operating system) as the fuel mixture table without any O2 feedback as long as table
- {B4205} Closed Loop Temp Enable is also set to it's maximum value.
If this parameter is enabled then O2 feedback (STFT) will be used with the Open Loop table.
If you wish to run total open loop disable this parameter and set
- {B4205} Closed Loop Temp Enable to it's maximum value.
Only the following values may be entered into this table:
- Disable
- Enable

Does this do the trick?

[The Alchemist]

did all that....didn't work, will have another crack tomorrow, maybe I missed something

[JezzaB]

did all that....didn't work, will have another crack tomorrow, maybe I missed something

Be curious to hear how you go. Going to try this very soon

Jez

[Redline Motorsports]

Waiting to hear as well. Just haven't got to mine yet.

Howard

[GMPX]

Sorry guys, I missed this discussion.
B1506 is the key. What happens even in 'open loop' if it could be called that is the ECM will still look at the O2 sensors once it decides they are at a working state (i.e, hot enough and voltage swinging).
Via B1506 you need to make the ECM think the O2 sensor is never ready, drop it way down in value.

Cheers,
Ross

[The Alchemist]

:Eyecrazy: hey cool thanks GMPX...who would have thought.... :Eyecrazy:

[hymey]

Hi fellas.

How is the SD open loop tuning going.

To disable LTFTs

B1508- LTFT enable. set to 140 deg C(must go over this to switch on)

B1509- LTFT disable. set to -40deg C(must be under this to enable)

B1510- LTFT MAP disable- Set to 256kpa- Must get above this value to enable.

I have my LTFT disabled all the time with MAF tune.

Now to switch off STFT(want to SD open loop tune my car), the info you guys listed isn't exactly clear. B1506 gives a list of parameters in which I can't find any values there to switch off STFT.

only B1502- sensors switch on after specified ECT is reached.

B1504- ECM checks to see if sensors are ready for closed loop once ECT has reached specified value.

Do I set these to 140?

Cheers

Joel

[ntae]

I still got my trims working when the 02 sensors are pluged in ,besides sitting there flashing the E38 for 1/2 a day working out what/if stops the trims . has any one stoped the trims working through changes to the tune file

[hymey]

Yes, have u stopped LTFT and STFT or one of each or neither.

I fiddled for a while and this worked.

B1510-256

B1504-256

B1502-256

B1508-140

B1509-40

B1511-0.00

B1512-0.00

Not all these changes may be required but I just kept fiddling till the trims stopped and this is what I ended up with.

BTW I am from Gladstone. Shoot me a pm if you need some advice or vice versa.

Cheers

Joel

[RetroAus]

I have tuned a cammed L98 using E38 ...using Auto VE...Have to write the PIDs but it works a treat .Just make sure it is in open loop....

[hymey]

What wideband are you using Retro. The latest update already has a BEN factor PID listed for Innovate widebands and a few others.

[RetroAus]

I am using Motec with NTK sensor. Current version has BEN PIDS for GM.AFR only as far as I could see...PID for E38 Commanded AFR is called E38.AFRATIO_DMA. So you will have to write one using E38.AFRATIO_DMA PID for BEN factor..

[hymey]

Here is my calc pid. How does it look?

[RetroAus]

Calc PID looks as though it should work..Just try it out .

[hymey]

I noticed the factory O2 sensors are after the cast not before. Just wondering if this will give inaccurate readings with the w/b.

[RetroAus]

There are 4 oxy sensors....2 pre cat and two post ....

Pre cats are used for fuel trimming

Post cats for monitoring cat condition for emissions...

[hymey]

Thanks, I was under the car yesterday and I only seen the ones after the cats, I couldn't see anything before.