VN S1 V6 w/ VS MAF 728

[HoldenForever]

Hi,

I put a VN series 1 V6 into a VS body and plumped up the MAF and got the electronics hooked up no worries. Its not running the cam angle sensor. The car will start up and run fine and it drives fine after advancing the entire spark table up towards the 808 tune spark table. The only problem I am having is the engine stumbles just as I first move the throttle down. I have datalogged it and found that the advance goes to 23035 then 0 then slowly back up to 10. I am guessing burst knock is coming in and retarding the timing to 0 so the engine looses power and begins to stall then stall saver kicks in and saves it?? When its cold the stumble is at its worst when it warms up the stumble is not as bad. You will see the RPM drop right off as soon as the TPS moves in the data log. Please help

I am using:
BWPJ1640.bin
VS V6 v1.24 %2451.xdf
%2451 VS V6 Engine and Trans v1.10 WB 14.7kit.adx

I have added a datalog too.

[VL400]

The crazy 23035 value is due to the spark advance item in the ADX not being signed. It would have been negative spark advance, ie sparks after TDC.

Whats the bin got in it at that load point?

[Holden202T]

try fiddling with accelerator inrichment settings.

[HoldenForever]

Cheers for that signed fix. Here what I got:

RPM MAF HZ G/S Milli/C TPS% Advance
894 2928 8 176 0 14
914 2928 8 176 2.34 14
914 5017 12.4 340 2.34 -4
679 5017 12.4 340 21.88 -4
679 3953 17.1 680 21.88 -13
325 3953 17.1 680 22.27 -13
325 3203 9.3 156 22.27 1
1340 3203 9.3 156 0 1

On the main advance spark table, the Milligrams/Cylinder only goes to 593. In 593 flow between RPM 400 - 1200 the advance is 0. I am a bit off the scale here?? I had a look on my good VN tune and it has 10 in the low revs at 1bar so I am going to try changing the tune to match my VN tune by advancing in the low revs at high airflow. Wouldn't being off the scale soo far invoke a scaler??

[HoldenForever]

try fiddling with accelerator inrichment settings.

Theres alot of settings. I'll try "Acceleration Enrichment - P/N % Extra Fuel V's Coolant" first then work my way down. I am just increasing the values around 8 - 100 degrees temp and hope it squirts more.

[charlay86]

try fiddling with accelerator inrichment settings.

Theres alot of settings. I'll try "Acceleration Enrichment - P/N % Extra Fuel V's Coolant" first then work my way down. I am just increasing the values around 8 - 100 degrees temp and hope it squirts more.

that first one is for when you are in park / neutral so probably won't help.
I think your spark advance should be increasing not decreasing when you open the throttle...
Cylinder Air Mass (mg/cylinder) is not directly equivalent to manifold pressure, so you can't directly copy the spark table.
What does your spark table look like?

[HoldenForever]

I have changed the main spark table to advance more at high flow low revs and its made things ALOT better. I was wasting time changing everything else other than the main spark table. Its no longer dipping to the negatives and stays around 15. I am on the right track I think, I just have to keep modding the spark table till its a good drive.

I have included a pic of the spark table I am using, its a work in progress. Any pointers would be appreciated. Thanks for your time so far guys.

[charlay86]

Try to keep the table relatively smooth looking, in some places you have jumps of ~14° between adjacent cells which is a fair bit of a jump.