Another first time RT tuning - TT VN V8

[admj1]

Hello to all.
Yet another 'first time RT tuning' thread.
Thought i would document my progress..

Car summary is as follows:
VN V8
T5 gearbox
VT 195i roller motor
2 x gt2560 equivalents from nissan s14 SR20 (t28)
twin 2.5" turbos back
walbro gss342
2 bar MAP
bosch 42lb 'greentops'
innovate MTX-L
usb conv VS man ECM / NVRAM etc.

Attached is my mods to the BLCF base bin which i carried out, the bin/log and an XDL of the start.
For some reason wideband seems to indicate >22 AFR..
Timing is steady at the 23.XX demanded by the bin.. how can i tell it is in idle mode - is there a flag??
It has an enormous hunt too - Im not sure how to approach adjusting VE's and the like with the hunt - cracking the throttle open still results in a hunt of 400rpm or so..

My initial plan was...
start engine
get up to temperature..
rev a bit higher, reset IAC motor..
review idle AFR against WB afr... adjust idle VE on main VE table till they are right...
Set idle speed to 600rpm
review idle AFR against WB afr... adjust idle VE on main VE table till they are right...
reset idle speed to 800rpm
adjust idle spark, adjust so that you get max vacuum (lowest map reading) (dont go over 30deg!)
copy idle spark to main spark at 800rpm.
reset idle speed to 600rpm, set idle spark for max vacuum, review figs and interpolate into 400rpm mainspark table??
reset idle speed to 700rpm and reset idle spark for final time.
Re-enable idle spark adjustment.

Thoughts on how to initially approach idle - why is the wideband showing it as being so lean?

[VL400]

For the wideband check that the MTX-L analog output is setup as the default figures and/or matches the two items "VE Learn Params - WideBand 0v AFR" and "VE Learn Params - WideBand 5v AFR". Maybe chuck a multimeter on the analog signal and see if it hovers around the 2-3V mark (2.5V is 14.7:1). Check that its wired to pin D8 of the ECU.

The hunting looks like idle spark working overtime to try and stop it. Could be a range of things, the VT cam is fairly different to the BLCF bin so wont be happy. Will need to get the wideband going first and see whats happening. Can turn it off using "IAC - Idle spark Adjustment params - IAC spark correct'n lower coolant threshold" and making it 151deg.

[admj1]

the wideband reading from tunerpro is indicating the same as the MTX-L gauge.. + i calibrated it in fresh air as per instructions..

in another thread (https://pcmhacking.net/forums/view ... 425#p23595) mentions..
'5 - open "Injector - Injector Bias vs ADINJ" and add about 0.6 to the whole table'
what is that table/what does it do?

i already turned off what i thought was all the corrections - including the iac idle spark correction.. (see the text file for everything i changed - i got the info from cruising round this site for the last few months + reading all the guides)
below is the auto update/idle parts i changed..


Disable VE learn (wide or narrowband)
'Scalar: VE Learn Params - Low temperature limit'
Original value: 80
New value: 150

Disable BLM updates
'Scalar: BLM Params - Block learn LOW temp limit'
Original value: 80
New value: 150

Disable closed loop (norm and idle)
'Scalar: Closed Loop Params - Closed loop minimum coolant temperature'
'Scalar: Closed Loop Params - Closed loop minimum coolant temperature'
Original value: 44
New value: 150

Disable lean cruise
'Scalar: Lean Cruise Param - Minimum coolant temp for Lean Cruise'
Original value: 85.25
New Value: 150

Disable idle spark adjustment...
'Scalar: IAC - Idle spark Adjustment params - Idle spark correction limit'
Original value: 5.27
New Value: 0

Disable idle fuel adjustment....
'Scalar: Idle Fuel Param - RPM above desired to begin Lowspeed enrichment multiplier'??????????????????
Original value: 0
New Value: 1000

Change commanded idle speed to 800rpm (so sits right on one point)
'Table: IAC - Desired RPM for manual trans vs battery voltage'
Original value: 750 (manual).
New value: set to 800 (manual)

will try again tonight when i get home - hopefully the battery is charged by then..

[Jayme]

in another thread (https://pcmhacking.net/forums/view ... 425#p23595) mentions..
'5 - open "Injector - Injector Bias vs ADINJ" and add about 0.6 to the whole table'
what is that table/what does it do?

that table is the correction for the injector opening delay, injectors obviously dont open straight away when you apply power, so you need to tell the ecu how long it takes for it to start flowing fuel. in the other thread, he was using 60lb siemens injectors, and I normally add about 0.6 to the table to correct for the longer opening time of those injectors.

[admj1]

okay i have 42lb bosch injectors - set at 45psi base pressure..
standard 304, my injector constant is set at 0.0603 (standard was 0.1466) - however at this value when idling my VE's seem way way too high, needing (for example) at 1000rpm, 40kpa, A VE of 92 to match the commanded AFR + get it to stabilise..
if i change the injector constant to 0.08/0.09 it seems to be more agreeable with the stock VE's and not have AFR >20...
do i need to correct for the longer opening time of the injectors?
on the weekend I will re-check the fuel pressure too..

[Holden202T]

at the end of the day the right injector rate is the one that allows you to have the VE table minimums and maximums between 10-90 so if you have to offset it to get the 100kpa highest cell at about 90 then so be it, and aslong as the lowest number is not below 10ish then it should be fine.

i've done a few tunes where the whole lot is almost sweet but its just hitting 100ve on some 100kpa cells. so offset the ve and inj rate by 10% and it is almost perfect then!

i would have expected your extra fuel pressure to have made it rich rather than lean, but it may also be that the extra pressure behind the injector makes it slower to open ???

[admj1]

fuel pressure is set to fraction under 3bar..
fuel flow is not an issue..
I realised fuel pressure bounces around (a lot) without the dampener installed so i reinstalled it..

however, even when i change the injector constant from 0.06 to 0.085 - it still is extremely lean when the revs are brought up, although idle afr is extremely rich...

any suggestions before i start suspecting ecu or injectors - this engine ran fine on a stock kal3 blcf (200kw) 2 bar tune with standard injectors..
all i have changed is injectors (with brand new 42lb), fuel pump and ecu..

i have attached the bin file as it is (with the VE copied from the 200kw tune from here and interpolated across the increased resolution)..
i have two logs, one with the injector rate correct at 0.0603, and the other at 0.085 to test...
i am resisting any adjustments to the tune atm as i am suspecting i have another issue - have i stuffed something else up in the tune - initial settings?

otherwise im back to step one, replace the new injectors with the old and the delco-hack ecm with the kal3 ecm and start over...

[antus]

can you post up the kal tune?

[VL400]

You are ending up with some tiny pulse widths at light throttle - at idle its around 1.5ms but then it dips in to the 1.1 and lower range as soon as the revs are brought up. This might not be opening the injectors long enough to deliver the intended fuel. For a quick test (and prob easier than putting the standard injectors back in) try getting the ECU to change from double fire to single fire for low PWs - the ECU will detect that the delivered PW is getting too small, and instead of firing two small fuel shots per cycle it changes to one larger one per cycle.

Set "Run A/F Param - Minimum BPW for sync double fire fuel delivery (Min Value)" to say 2ms and "Run A/F Param - Minimum BPW for sync double fire fuel delivery (Upper Value)" to about 2.2ms. Any time the requested PW is below 2ms it will change to single fire mode and once it goes above 2.2ms it goes back to dual fire.

[admj1]

problem solved - the injector pulses were too brief.. changed as suggested and problem is solved..
now have a steady 600rpm idle.. thanks to all.

i had considered the injector pulses but assumed idle would have been their lowest value - i guess the auxiliary load doesnt change much between 750rpm and 1500rpm so it doesnt require twice the fuel, so the injector pulses become more and more brief..