Chasing my tail again with idle surge

[StupidJeep]

Hey all I thought I had my surging sorted but seems not. I had made progress in open loop so I thought. Started idled in P/N and in drive, now spart throttle stumble or anything. fuel trims seem good. Put in Closed loop and surges all over the place. I cant tell if its a min airflow thing or a fueling thing or idle PID.

Can some one have look a the tune and log and give any suggestions please?!!
0820 tow log with idle surge.hpl
082023.hpt

NGC4 with HRT 2 cam

[Spray-Cam Hell-Ram]

You said that your fueling was good so I didn't mess with anything in the fueling tab or your VE tables. Only thing Ill say in regards to your VE tables is that to me anyway, the values around the idle area just seem a little on the low end... like 7-10%-ish low....but if fueling isnt an issue at all, then no need to worry about that. I also didnt mess with your friction base table. Im not to familiar with the pre-eagle friction tables so I just left it alone. Just hoping that table is correct because it could def be a factor pertaining to your issue. Otherwise, give this a try...

[StupidJeep]

Thanks Ill have a look at what you did and let you know how it goes. Been away so just getting back at things.

[StupidJeep]

You said that your fueling was good so I didn't mess with anything in the fueling tab or your VE tables. Only thing Ill say in regards to your VE tables is that to me anyway, the values around the idle area just seem a little on the low end... like 7-10%-ish low....but if fueling isnt an issue at all, then no need to worry about that. I also didnt mess with your friction base table. Im not to familiar with the pre-eagle friction tables so I just left it alone. Just hoping that table is correct because it could def be a factor pertaining to your issue. Otherwise, give this a try...

Well dang!! That made it 100 times better than I could figure out!! Much appreciated!!

Attached is the log after I made your changes if your curious to see the fuel trims. It does have a a real slight surge at idle but barely noticeable. if it wasn't for the droan from the exhaust you probably wouldn't notice!

spray cam CL.hpl

Many thanks again for your assistance

[Spray-Cam Hell-Ram]

Glad to hear it was an improvement. I looked at your log. Try this and let me know if it improves further or not. If not, at least you've got the first revision to go off of, but maybe this will lessen or get rid of your minor surge you are talking about as well as help with the slight variation in the fueling I saw.

[StupidJeep]

One other thing Ive noticed is that it doesnt down shift the same. which I kinda understand as the throttle voltages and air flows have changed a bit. Its really only if I really romp on it it will unlock the converter and maybe drop one gear but not the usual drop a couple gears and rip. I guess the question would be is it more making the trans parameters work with the new throttle and air flow table or power request or something else?

[PurpleRam]

Still have a stock converter?

[StupidJeep]

Yep.

[Spray-Cam Hell-Ram]

How long have you noticed this change? Have you tuned your tranny yet? Which trans do you have?

[StupidJeep]

How long have you noticed this change? Have you tuned your tranny yet? Which trans do you have?

Just recently I noticed.... However I will load a different tune and see if it was something else I did.

545

[StupidJeep]

So I loaded the attached tune from a while back. it doesn't surge, idles ok, drives ok but feels like slug. it does however kick down when you stomp on it.

current 0824.hpt
current 0824 kick down works.hpl

[rays04gtx]

8018 Aa.1(1) 1-2-23.hpt

What was wrong with that tune ? it was written with the stock convertor in mind.

Log Channel's Power Train Throttle request, and Calculated load .

[StupidJeep]

8018 Aa.1(1) 1-2-23.hpt

What was wrong with that tune ? it was written with the stock convertor in mind.

Log Channel's Power Train Throttle request, and Calculated load .

Honesty probably nothing. Other than me trying different things the more I read other posts and trying things. Likely got to a point where somethings worked and other didn't and the combinations may have got a little carried away.

[Spray-Cam Hell-Ram]

Any luck with that second one I sent, at least with the remaining surge?

[StupidJeep]

8018 Aa.1(1) 1-2-23.hpt

What was wrong with that tune ? it was written with the stock convertor in mind.

Log Channel's Power Train Throttle request, and Calculated load .

I couldnt find the powertrain throttle request...?

[StupidJeep]

It didnt like the changes at all
[ATTACH]136470

part throttle surge then stalled

[PurpleRam]

I couldnt find the powertrain throttle request...?

Not sure if you have it, been Awhile since I looked on a NGC4 for it.

Part of your issue is going to be that the stock convertor is too tight for the cam, ideally you want 2200-2500 stall at a minimum, for that cam , stock 545 Convertor is advertised as 1500 stall realistically it's closer to 1700rpm, the stock converter behind the 4.7s is listed as 2k but realistically they stall around 2200RPMs.


2nd set of attachments, try setting spark in the low 20's just above where it wants to idle and cap MBT table in that area to just .05% above what you try in the PT table.

3190 attachments are from my 04 SLT(4650 race weight) when I had the HRT2 cam in it, Large valve pre eagle heads, LX car Intake stock TB headers ,true 3 inch exhaust, X pipe 3k stall edge converter. 5.13 gears
it was making roughly 530 Flywheel, leaned it out to 12.50AFR and dipped to 11.60s ,(585-590HP) that cam can make some real power once it's sorted out.....at that point it'll shred a 545 trans

the more torque we can get your truck to make at Idle the higher it'll push stall up, too high and it'll surge,looking at the logs, your jeep wants to idle at 50-65 kPa , so concentrate on that block on the PT, MBT and spark Min tables, 800 RPS seems to be the target area it wants to idle at also, the last attachment I rescaled the lower section of the PT RPM scale, it'll give you more control in that area, for best results use that RPM scale on all tables that have RPM as a Colum value. there's more but I have to run .



keep in mind that you went from 190/195@ .050 to 220/[email protected] (30+degrees at .05)

[Spray-Cam Hell-Ram]

Yea, it was kind of an all or nothing adjustment. It would either get rid of it or the polar opposite. Thanks for letting me know though.

[Spray-Cam Hell-Ram]

Man, is he ever right about the timing jump there. Smoothing out that area will do wonders and likely solve your slight surge issue remaining. Your VE tables that I went through had a similar problem where a few areas just needed smoothing out to smooth out fueling changes as you go from cell to cell when driving around. Just try to adjust areas in both the spark tables and the VE tables where adjacent cells have larger differences between them and that alone should make a pretty sizable difference.

[rays04gtx]

Let me toss this in here, for this area of a tune, Pedal and Throttle Voltage are more important than %'s

Throttle Voltage tells us where Airflow is, and where we are on Power% Request table.
Accelerator Voltage tells us when the ECU is no longer in Idle mode , once APPSv goes over .1v the ECU wants to leave all things Idle, Unless Table 44216 & or 12982 says other wise.
Accelerator voltage also tells us when we jump to Power enrichment(Table 44442)

Also the higher(within reason ) we set Idle VSS (Table 44216& 12982) the less options ECU has to decide what spark value to use for idle , gray area is cruise Idle can surge under 10MPH because the Pedal Expected Table(35064) is looking for X amount of power(Tq) and the Spark/Total air flow are giving Y , so there's a fight between PT,MBT and Spark Minimum Table.

Remember your Left foot , is telling the ECU what TQ quantity you want(Power% and Expected Pedal) , the PT table is the target to meet that request, if that request falls short it goes to the MBT to try and meet the request, if PT spark makes too much "Tq/Power" for the request it looks to the Spark Minimum table for the lowest spark value it can go down too (for that respected RPM area) VE and TAF play rolls in this also, but spark is the foundation, because the ECU is always going to target Stoich value for AFR.