Vn v8 cammed stalling when put into drive

[vp304]

Quick run down on car
Family member of mine rebuilt 5l in vn auto.
Cam with around 220 duration very slight lump at idle.
No hi stall. Yes i know a small stall would help.
Does not bang when put into drive etc and drives decent.
Stock intake manifold stock tb
Stock injectors
Has extractors usual 3 inch exhaust.
I am running 12p on it has been for over 8 months now tuned on the street with wideband.
Fuel Mixtures are good all round.
Of top of my head have adjusted the idle screw to have around 20 steps of iac at idle and looks like iac is working as it should.
Car drives good all round. Starts from stone cold and runs good

Tho has this odd time when you start it only when warm put into drive it just stalls straight away.
All sensors look like they are working ok and no check engine light or faults that i can see. I have not logged it yet and looked over log.
Is random and happens maybe 1 in every 5 times or so of putting the car into drive.
I have read up about some cammed cars needing to be slightly richer at idle so have tuned it to around 14.0 afr at idle. ?

Here is some screen shots of the tune below. Does anything look out of the ordinary ?
I have never tuned a car with aftermarket larger camshaft before so dont know a heap.

Any help will be appreciated thanks

[hsv08]

I would probably tidy up those sub 12 commanded AFRs in the cold engine AFR table, I can't remember if it uses that table or if there is a separate startup / idle AFR table without looking at 12P.
But remember that the engine always reads atmospheric conditions when about to start, with a cammed motor you have even less effeciency / vacuum then a engine with a wider LSA at low RPM depending on the cam. So for completeness, I'd just remove all that extra fuel around those zones.

Normally I'd add a couple extra degrees in the lower 400rpm zones to aid as a backstop if idle drops below to try catch it when it stumbles, you will always catch it faster with timing then with IAC.

['quipt4it]

This would probably idle in the 50'ish KPA map.
Set the Idle Spark map to match the Main Spark map. 25-26 degrees would be a good figure from 30-50 KPA. Could even use more.
The VE Map @ 800 RPM/ 40, 50 and 60 KPA could match that 41.41 figure (adjacent) too.
Leave the idle AF/R in the main table until you do this first.
Maybe move the IAC Desired Idle RPM in Drive up a little.
Log would be handy as well.

[vp304]

Thanks for the tips so far guys. I wont be able to get to the car till next weekend now.
But will fix up anyways those cold a/f ratio 80 90 100 kpa mega richness there.

Of top of my head mighta been around the 50kpa at idle in neutral then jumped a little to the right of the ve map when put into drive with foot on the brake.

Cause of size of the cam (and standard stall converter) i cant really bump the idle up in drive up much more as i think it causes it to bang when going into drive.

So
Idle spark advance all up around 25 deg in that table.
Then on the main timing map
400 and 800 rpm areas all up around 25 deg around the areas were the car idles at in park and in drive ?

['quipt4it]

Plus bump these:

..The VE Map @ 800 RPM/ 40, 50 and 60 KPA could match that 41.41 figure (adjacent) too...

VEmap.jpg (107.6 KiB) Viewed 3098 times

Your Desired IAC RPM in Drive is only 750, try moving it up 50 RPM.
The IAC Params may also need fine tuning.

[vp304]

Plus bump these:

VEmap.jpg

Your Desired IAC RPM in Drive is only 750, try moving it up 50 RPM.
The IAC Params may also need fine tuning.

Is that smoothing out of the say 40 -70 ve map at 800 rpm to (41 ve or so) help stabilize the idle air fuel ratio as cause the cam is lumpy at idle it may jump around in the cells a little bit?
Sorry my wording maybe a bit out dont know how to explain it.

['quipt4it]

Mainly just to add in some extra fuel.
That's around 8% you won't have to find elsewhere...
Is the idle stable?

[vp304]

Idle is probably what you would expect for cam of this size. Dosnt hunt crazy or do anything stupid besides that odd stall when put into drive when cold here and there.
Il give all those bits a go next weekend and see how it goes
thanks

['quipt4it]

Did you mean when warm^

...Tho has this odd time when you start it only when warm put into drive it just stalls straight away...

...I have read up about some cammed cars needing to be slightly richer at idle so have tuned it to around 14.0 afr at idle. ?..

The stock Max Coolant Temp scalar setting for the Cold A/F R table is 44 degrees. Either change the scalar to 32.00 degrees, or change the figures circled to, say 14.20 (A/F R). Otherwise these figures will over-ride the A/F Ratio - KPA 20-100 Air Fuel ratio vs RPM and MAP at these thresholds.

coldtable.jpg (97.25 KiB) Viewed 3085 times

[VK_3800]

I can't see it being a fuel issue with a small cam like that? Bring the timing up in the 400rpm range so it doesn't get retarded if it bogs down momentarily and reduce the 800-1200rpm gap, its probably happy to idle at 28 degrees too which will probably help improve your idle vacuum.