Please Help With Stalling and Idle Hunting/Surge!!

[LSXtreme]

I am done messing with this thing. I have spent over 20 hours trying to get it to not stall after a rev. On the upside I finally got it to NOT stall after startup hot and cold so that is a plus. However I am at a loss here. I don't know if its the addition of a lighter stall converter or the intake and headers but its the same engine that ran perfect in my truck, but it had an Electronic Throttle. Now that I am cable driven I can not get it straitened out!!

I have tried a ton of different combinations and all end with the same result... Stalling...

Currently the TPS is set to .65 volts and added another hole in the TB blade. Converted to 1Bar SD to see if the MAF was the issue and it still runs the same. Raised the RPM Errors a little in the adaptive idle since it has a cam, not luck. Doubled the Airflow to all the P.I.D tables. Helped a little on settling into idle after startup. Put IAC Steps back to stock as the TB and IAC are stock. Have the RAF close but with the idle surge its hard to get a solid number. Lowered adaptive spark to +2/-2, matched Idle Spark Advance to the Main Spark. I noticed the LTFT's are way rich as I smoothed the VE table last night and I think I richened up the idle area by accident so that is why the trims are rich.

Also, what has got me scratching my head is the STFT's. Why are they so sensitive and follow the O2 oscillation?? Off throttle the STFT's are all over the place and I cant find out what effects that.

Need some help on where to look at on getting this tune cleaned up. I hope by looking at my scan and data that someone can see right away what the issue is.

Thanks

Here is my tune/scan/config:
1 Bar SD RTT (SD ONLY) v8.hptStalls after Rev.hpl(AS)Idle Tuning.cfg

[LSXtreme]

Ok Starts up at any temp and settles into an idle beautifully. However after a rev it will swing low then recovers but its gets worse after about 4 swings then dies every time. Tried to pedal the swings out with no luck.

Attached is new tune and scan:
1 Bar SD RTT (SD ONLY) v9.hptv9.hpl

[LSXtreme]

Could it be my VE table causing the surge and die? Also, my brain is fried from looking for answers... but if wanted to always run idle in open loop.... is the only way to enable PE at idle but at the idle RPM disable enrichment? If not, what is the best way? And how is the throttle response when it switches from Open to Closed Loop on a rev or off idle?

[JakeFusion]

Those IAC counts look high, especially with that much voltage on the TPS. And you drilled a hole in the TB? Hmm...

[LSXtreme]

I just opened one of my buddy's scans from which I am running the intake off his car (FAST LSXRT) and we were having the same trouble with the high IAC counts after TB adjustments and stalling after a rev. Its got the FAST adapter plate so I can run a stock TB so not sure if that is causing some of the problems? But similar issues with 2 different setups but with the same intake. Now that I am thinking about it... I want to say my buddy's setup was a low compression for boost like mine is. (I am just thinking out loud)

Any know issues with these intakes? Or tips and tricks maybe? I have never had this much trouble on any engine other than with this intake on them.

[gagliano7]

Your raf table seems high. Did you do the Russ K idle config from a cold start not touching the gas pedal? What are your iac count when car is at warm idle? You could have a vacuum leak that you are trying to fix with the tune. Do a smoke test on the manifold.

[LSXtreme]

No vacuum leaks. Wouldnt a vacuum leak lower the RAF as it would be getting more air? Yes, I used Russ K Idle config. What I have found out to help the stalling is the P.I.D Tables.

[LSXtreme]

One thing no one has noticed that I happened to was the IAC jumps around way way to much. I Pulled a scan from one of my other cars and the IAC only moved like +/-5-10 steps when needed. On my scan the IAC jumps +/-20-30 constantly. What tables effect the sensitivity of the IAC? Is it adaptive idle? Like I said before I have been mostly messing with the PID airflow tables but I think all this is doing is pulling air and trying to not make such a big recovery when needed because then it will spike too high when it recovers and the surge starts in and leads to eventually stalling.

So should I raise the RPM error of the adaptive idle?? I notice the rpm with my cam will fluctuate +/-100 rpm roughly but thats not to say the IAC is causing this because it jumps so much. I can manually set the IAC to 85steps and the idle holds pretty good for a while. Since the cam has a little stutter every now and then and with a +/- 2* of timing to help recover I dont think it is enough sometimes.

My main goal here is keep the IAC from jumping all over the place during idle. Any suggestions will be greatly appreciated!

[mecanicman]

Fix your over/under speed spark tables so the iac does not have to work so hard. Generally rpm 0 is 0, values are progressive as rpm deviates more either higher or lower, right now yours does not do much. Go into park/gear idle timing tables and make 0-800 18 for all cells.

[LSXtreme]

Ok I will try that.

So this may be a dumb question but I have always wanted to ask it.... How can a carb maintain a steady idle without having an IAC for air control and an electronic ignition with high/low rpm adjustments????? I should be able to pull the plug on the IAC and set the timing to 18* only and it should idle and recover from a rev just fine right?

Why am I not understanding why this is such a difficult thing to which is .... IDLE!

[edcmat-l1]

There are several things contributing to your stalling issue. One of them is your VE table. Need to take some "fuel" out of it at idle, and in the 400 rpm column. It looks like you've only dropped it in the 800 and 400 columns, the rest of the table looks stock.

Turn off the LTFTs and dial in your VE much closer, especially in the 800 and 1200 columns.

And BTW, if you have too much pump shot in a carb, if you blip the throttle and let off quickly, you'll make the engine stall. Most of the time when a motor stalls after blipping the throttle, it's just a matter of too much fuel.

[blue7two]

Where you able to fix the stalling after rev? I am having the same issue.

[LSXtreme]

blue7two, yes, after pulling my hair out I decided to zero out all the P.I.D airflow tables and only allow the timing to maintain the idle speed by giving the over/under +/-6* to play with. Idles and recovers just fine for now so I can actually get some driving time in. It was acting like the IAC was stuck in a loop because it was too slow (or fast) to react to the last RPM change.

Unless someone can explain the correct way to dial in the Proportional/Integral/Derivative Airflow and filter settings, I am running without it. The downfall I see already from not using those tables is the recovering from a big dip in RPM or compensating for different loads at idle as there would be no way to recover unless you do it manually with the pedal as timing seems to be best for +/- 150rpm