New CAM and Idle Assistance

[joecar]

Might be my internet...

[Behold]

IAC hold the RPM at the RPM set (800 or 900 had been tested) I need to check IAC steps.

I need to log idle field again (this weekend) to see what its doing now.

Base Air seems to be set right. Its about 14.7-8 on tickover maybe a little too rich still if the WB is miss reading a bit. but any leaner it seems to not like it as much. I have added and removed spark with about 21 degrees being the best on tickover. it floats from 16-23 I think as it ticks over. tick over is actually

Follower as @joecar says could be to blame. not fully sure as even if its been ticking over and I turn the wheel. and it can stall under load from the PAS. No throttle touched. this is more of a problem when warm.

[statesman]

Have you tried what was suggested to you here?...

I get enough airflow so when there is no load the last bit of idle RPM is spark trimmed. So when load is placed spark returns and air can be added by IAC as it is needed. The way I see it all base engine load has to be taken care of without idle air trim.

This will work provided you make your spark corrections a bit more aggressive.

[Behold]

sorry for going a bit quiet. Lots going on.

I have*tried Spark*corrections, RAFIG setup and Follower alterations.

The issue is better but not 100%.*Still coming to a stop from speed (30+) no throttle touched on deceleration it will likely stall.
Warm its worse and seems more likely*to stall*from the same*scenario.

if its about to die I can recover from 400RPM or less (seen 250rpm before)*with a kick of the throttle.

I know many say bigger holes or moving the*blade is not right to*do but surely there is merit to need this? the older LS1 with cable*either uses a stopper on the blade or a hole in it. some a combination of both IIRC.*
Having worked on*another*vehicle with a larger than stock cam that was tuned (not by me) to not stall using follower.*It just seems a*hack to cause it to hang to increase likely hood to not stall.*This*is an LS3 with ETC so it can hold the throttle open effectively making a larger hole.

I'm really at a loss and maybe my ECU tuning limit right now to get any better result and I do just wonder how much*we are trying to*fix an issue that has a physical*engineering limit.*Don't get me wrong I fully belive the ECU needs altering hugely to match the new modifications but surely its*like*trying to electronically alter the intake pipe to a larger diameter to get more air in. you cant do that.

I might be opening a can of worms here! Thanks all

[statesman]

Post your tune file.

[rich24v]

sorry for going a bit quiet. Lots going on.

I have*tried Spark*corrections, RAFIG setup and Follower alterations.

The issue is better but not 100%.*Still coming to a stop from speed (30+) no throttle touched on deceleration it will likely stall.
Warm its worse and seems more likely*to stall*from the same*scenario.

if its about to die I can recover from 400RPM or less (seen 250rpm before)*with a kick of the throttle.

I know many say bigger holes or moving the*blade is not right to*do but surely there is merit to need this? the older LS1 with cable*either uses a stopper on the blade or a hole in it. some a combination of both IIRC.*
Having worked on*another*vehicle with a larger than stock cam that was tuned (not by me) to not stall using follower.*It just seems a*hack to cause it to hang to increase likely hood to not stall.*This*is an LS3 with ETC so it can hold the throttle open effectively making a larger hole.

I'm really at a loss and maybe my ECU tuning limit right now to get any better result and I do just wonder how much*we are trying to*fix an issue that has a physical*engineering limit.*Don't get me wrong I fully belive the ECU needs altering hugely to match the new modifications but surely its*like*trying to electronically alter the intake pipe to a larger diameter to get more air in. you cant do that.

I might be opening a can of worms here! Thanks all

Excuse if totally irrelavent to your cause....
Does seem to be a fair amount of stuff that just doesnt work when going maffless....I assume you refer to my ls3 E38?....BTW very grateful for your help getting up and running to point I'm not too scared to try changes myself.
The table we modified was B1860 Airflow dec rate ?....I'm not actually sure this did the trick, more likely as you got closer with the VVE at the same time that was more help. ( It still suffered stalling with small parking manouvers ect.)
I subsequently made bigger and bigger changes to that table with little/zero affect.

Couple of days ago I compared the B1829 Min Idle Airflow table with the HPtune table after coverting the units ect. The HPtuner table numbers at low rpm were almost double, so I mirrored the settings into B1829
Bingo....sort of....drop to idle now behaves like the hptune where rpm will drop to just below target (not as much as before) and pick up by ~120rpm above target before settling to target after about 7 secs or so.
Still an annoying idle hang period, and I know it's probably viewed as a bodge, I will try reducing the table bit by bit. For now though it's much better than before and a lot less likely to stall on me.

[Behold]

V11.8-PE124-COS5.ctz

Played a bit to day.1 thread movement on my Throttle stop has massively resolved the issues. Still not perfect and 2 threads was too much it hung quite a bit. but I guess a new RAFIG tune will be needed now air expected will be more that it should be.

Thanks

[spy2520]

I've had that issue and played with idle settings alot. I think I'm around 24* and 13g/s with much improved results. Cam specs are 236/238 on a 113 LSA. Leaning out the idle cells in the VE table also seemed to help.

[Behold]

I solved it in the end. Still needs fine tuning but opening the throttle plate a fraction ( I really mean a fraction) and it now idles like a dream. No hanging no stalking easily unless turning the wheel a lot on parking.

I'm sure it can be made better but it's worlds apart from before. I tried advance, leaning. Nothing worked.

[spy2520]

Yeah I forgot to mention I did have to drill the TB, tried opening the throttle plate but I guess with this cam it just needed too much.