Need help with crazy AFR issue with dead spot

[VTXU8]

What I see in the graph is a problem with the commanded air fuel ratio not the actual reading from a wideband. Have a close look thru your tune at that point and I'm sure you will find it.

That's what I don't get. I can't see anywhere in the tune where it would command an AFR of 25.5. At that point the actual AFR goes to nearly 20. Which is the max limit readout of my gauge Spartan 3 WB kit.
I have just drastically changed all the PE tables via the Pe Spreadsheet. So I'll see if that makes any improvement next time I take it out for a drive. It's the only thing I can think of. Unless the memcal is corrupted in some way but unlikely.


Here is the bin and Xdf for reference:

AE TUNE5 10-09-23.bin

(128 KiB) Downloaded 62 times

VT_V8_$A6E_Enhanced_v1.00.xdf

(189.61 KiB) Downloaded 58 times

[vlad01]

I thought the VE equiv was something like grams/s of air from the MAF?

[VTXU8]

I thought the VE equiv was something like grams/s of air from the MAF?

I'm not too familiar with tuning VE on map based vehicles. All I know is that you change VE tables to dial in your fueling to get AFR's spot on or in the ball park.
With The 1's Enhanced code, he has made the Maf tables linear up to 510G/s @ 16,000Hz and you don't really need to touch those table unless you go to a Card type maf setup where you would play with the maf scalars. At least, that's my understanding of it.

Instead, you use the INJ. Rate Constant vs mg/cyl vs Rpm table(after you set your Base Injector rate) to fine tune to desired AFR's. Plus there are many other variables that will need to be tweaked such as batt. offset etc. But that's the main table you would use.
I probably butchered that explanation. Still learning.

inj.multi table.jpg (159.7 KiB) Viewed 1817 times

[VTXU8]

So a bit of an update:

Adjusted PE tables and finally got the car to go into PE. This time at 40% tp. I still need to tweak the PE tables a bit as now the ECU is commanding 10.7 instead of 11.5 afr in PE. Better than 25.5 Goes to show you need to be careful of zeroing out parts of PE tables.

Looking back at the log I can now easily see I need to adjust my Inj. Constant table a lot in the higher end of the table as the car still cuts out and leans out badly. But I can now go over 50%tp and can see where she needs more fuel.

I do have a DTC 97 now (CCP Driver Failure). Is this an ECU or a mechanical issue with the Purge Solenoid?

[The1]

Bin looks weird like its corrupt, ive taken stock Enhanced bin and copied your tables over, reflash this whole bin to your nvram and try again.

Make sure your using the enhanced xdf and adx.

[VTXU8]

Thanks mate.
Will do. See how it goes and let you know.

[VTXU8]

@The1.

I tried to flash whole BIN via OSE tool. But the 'Write Bin' option is greyed out. I'm sure it was before.
These are the settings i'm using in Preferences below:

OSE2.jpg (71.65 KiB) Viewed 1693 times

OSE1.jpg (61.91 KiB) Viewed 1693 times

EDIT:

Looking at the Flashtool instructions. It looks like you can only write Bin on 12p or Flash based pcm's. So I will need a re burn.

[VTXU8]

So a little update:

Yes, the BIN was corrupted as suggested. So I ordered a new nvram off Gareth with new updated xdf. I couldn't copy whole bin that The1 fixed for me using the Flash tool, as that option is not available. I will send my old nvram for a re-burn and I will have a backup.

Went for a drive and logged it. I now have much better data coming through and can see that it needs a lot of work on the inj. multiply table in the high end. You can see when it goes into PE and is commanding afr correctly but it leans out dramatically at that point and basically cuts out until i back off the peddle.

There are some issues I think are hampering my efforts to get the fueling right. Probably more a lack of knowledge on my side.

I have set Open Loop AFR's but in TP, The commanded afr is always showing 14.6 when it should be for e.g. 12.8 etc at certain points. Commanded afr will only change correctly when I'm in PE. Then goes back to 14.6 when it should be showing 12.8 or what ever I have set Open Loop afr's to. Is this normal?

So with that in mind. My WB CORRECTION AFR vs TARGET AFR History table is only correcting the fueling to achieve 14.6 afr instead of whatever I have commanded in Open Loop afr table? How do I adjust my INJ. Constant tables to reflect the afr's I'm asking for? Just get all the tables set correctly to achieve 14.6-14.7afr then add more adjustments after till I achieve the desired afr's?

Thanks Vlad, The1, Charlescrown for chiming in so far

[VTXU8]

Looking at my last log.

It seems that the ECU might possibly be stuck in Closed Loop. Right from the start I have been making my fuel adjustments based on my WB AFR Correction histogram table. I realised that the corrections are based on a constant afr of 14.6 and not what I have commanded in the Open Loop AFR table.

If you look below, you can see the WB AFR Correction table. And at the highlighted Cel it shows a figure of -7.064. The actual afr at that Cel is 13.569:1(pic below). Doing the simple math of 14.6-7.064% = 13.569(rounded to) or 13.569+7.069 = 14.6(rounded to).

new widebband correction.jpg (129.79 KiB) Viewed 1518 times

new wb afr table.jpg (135.62 KiB) Viewed 1518 times

At these points. The commanded afr is always showing 14.6 when it should be 12.8.

new monitor 12.8 afr.jpg (78.07 KiB) Viewed 1518 times

new open loop.jpg (145.78 KiB) Viewed 1518 times

Below are the settings to turn off Closed Loop. But looking at them, I think that they may need to be set in the opposite direction.
E.g.BLM High Temp Cut Off should be set to 0 degC not 151 degC?

new blms.jpg (35.42 KiB) Viewed 1518 times

Not really sure where to go from here. I'm surprised I haven't killed my motor lol. I have re-done the whole fuel table again to give it much more fuel. But without the right fuel corrections in the histogram, I'm just pissing in the wind. I'm just glad I'm getting more accurate data now.

[antus]

I am not too familiar with the MAF stuff, but I think those BLM settings are temperatures that stop it collecting data for the long term fuel trim, not the closed loop. BLM is Block Learn Multiplier, which is your long term fuel trim (LTFT). It is possible that it affects more than just BLMs but you should check that. And I think you should be applying correction to the injector multiplier table, not an AFR table. If I am not right someone will correct me.