b0141 settings

[stigmundfreud]

Friend of mine has had issues with a tune thats been developed for his car so has decided to take things into his own hands and plunge for EFI, I should be on some sort of comission.

Anyway before he takes the final plunge he is going to borrow mine to do some logging to check out how everything is. All is set up to log but in preperation for possibly tuning his car I am setting the tune up for AutoVE.

His car is an LS2 with an E40 ecu. He has complained that since the return of the car that fuel economy is shocking. His tune is set to run in OL SD mode, maf and o2's disabled. LTFT, STFT all disabled.

Looking through the tune I saw table b0141. By reading the description it appears that if you are in Open Loop mode, that this is the table that commands the fuel levels when in gear?

In the tune, this is currently set to 1.46 AFR or 10.0 EQ, is this standard for this table? I have compared this to a hsv tune for the same engine and they appear the same, however, the HSV tune was running closed loop. So I guess this table, as it is only ever in OL should be updated for warm running in OL mode (similar to 3605 on the old GenIII ecu's?)

[pauly24]

I think you made a typo, it would be 14.6 AFR, which is the same as 1 EQ. If it is 1.46 AFR (which i highly doubt) then it would be trying to use ten times the amount of fuel.

Correct about B0141 being the commanded fuel when in gear (and OL mode). But don't forget you have the multipliers which can effect this.

If its programmed to run in OLSD mode and the tune is not perfect, then the actual AFRs may be off and the car has no way of knowing this so it cannot correct itself hence the bad fuel economy. It could be idling very rich, need to get a wideband on it and see what its doing, easier yet just enable the O2s and LTFT and watch what happens.

The tune probably has not taken into account for the variation in temperatures, theres a really good tute by swingtan on how to do this.

All factory cars run closed loop.

[stigmundfreud]

I didnt make a typo it is currently set to 1.46AFR but take it the multiplier make take this up by 10? I'll have a look around. I cross checked this table against a hsv tune and it too was set the same but for hsv but their tune runes closed loop

[stigmundfreud]

just looked and it was my mistake, the ivt multiplier would bring the 1.46 up to 14.6. so thats ok, there is something wrong with the tune so going to put it into open loop and monitor the AFR's to see what is what

[swingtan]

Yes, for some really weird reason those tables look off by /10. All the base commanded fuels tables ( B0141 to 0144 and B0146 should all be multiplied by 10 to make them "sensible". These tables are also in the E38, but they read as you would expect. Try this, in B0141, hit the "+ .00" button in the top right of the TuneTool screen and it will add decimal places to the cell numbers. They are all 1.4630......

Simon

[stigmundfreud]

cheers! It was just odd to see a table represented like this.

My friend has had a partly wasted day in so much as the LC-1 failed, the bloody thing just died so no wb logging. Got to take the car out for a logged run and fuel trims are sky high, average of 24% ltft and higher in places STFT so safe to say the tune is off somewhat.

Will start a new thread to discuss the logs/tune