Idle & Off Throttle Hang - Sometimes

[Monarols71]

Thank you all for your previous help. I hope this is the correct place to carry on the discussions.

After reading heaps, comparing .bins, taking more logs, and googling my old brain until I have to have poppy nap time, I hope you can still aid me in finding this infernal problem.
After resetting the IAC as previously mentioned, we now find that the cold idle is not as stable as it was before I adjusted the idle screw, and the revs between gear shifts seem to hang a lot longer. I've put in another IAC valve, but that didn't make any difference, I've disconnected the cruise control cable, lubricated the throttle cable, checked for possible vacuum leaks and replaced the PCV hoses. Nothing has changed as far as the (sometimes) slow to return to idle revs is concerned.

First question: - Does the "IAC motor park position vs load" and/or the "IAC motor park position during crank vs CTS" tables have to match the IAC steps as they are in the logs??
Second question: - What is "Beyond RT area" table?? What is in the left hand column?? versus the Temperature Sensor.
Third question: - Is there a "decay time" or a "delay time", or something like that in the program, from on throttle to off throttle? A bit like the old Toyota dashpots that used to hold the revs higher during gear changes for emissions in the early days.
I'm just trying to narrow down where I should look next.

Any and all assistance hugely appreciated.
Kind Regards

[Monarols71]

Beyond RT Area - Calibration - Intake TS??

[The1]

that's the Intake Air Temp Sensor calibration, you would only mess with that if your not using a stock sensor, Beyond RT Area means it's beyond the Realtime Upload Area so if your using realtime you will have to reburn the nvram with the settings changed.

Not sure what your problem is are you talking about Park to Gear changes or 1-2 changes? What XDF? What Bin? need more info, there will be scalars that define IAC Steps between P/N N/P

[Monarols71]

Thank you. Apologies for not giving enough info.
We have a VS series 3 1/2 VS manual.
I've been using $A6 VS V8 Series3 V1.01 ADX lately, and a custom .bin. I hope that is the correct xdf, as the series 3 VS came with MAP and MAF engines. Ours is built after April 1999, so its MAF based (VT MAF roller engine).
We have a sticking throttle type syndrome. Every where else, the tune seems to be spot on, it's just the on\off city driving that makes it play up. I've played with some of the settings, but not knowing WTF I'm doing, I'm loathe to do too much "fiddling".
The scalars don't seem to match the actual IAC steps in the log.
The car idles perfectly when it's settled, but sometimes it takes a second or five. We have a baby cam that is probably throwing the idle off (hence the custom tune), and we use 95 or 98 RON petrol.
I'm currently also trying to sort the DFCO, as it will work, then not, then work, then not (feels like surging and logs show it), when going down hill with no changes whatsoever. But that's a minor issue.
Thank you for your patience and information.

[sparx-1]

Hi Monarols71 could you post the bin you are using and maybe your cam specs to
Cheers

[antus]

I noticed in my gemini which is a manual that the road speed to switch to idle mode was 5kph by default, and i'd sometimes be decellerating up to the lights and hit the clutch to prevent stall with the car still rolling at about 10-15kph and it was annoying me that the revs were holding up and the car was not going in to idle mode. I set the speed for idle mode to 20kph and now in that scenareo the engine rpm drops when i hit the clutch at the low speed.

In your case i suspect the decelleration fuel cut issue and the revs hanging up there might be the same thing and might be related to a specific road speed. Is your speed sensor present, working and calibrated?

[Monarols71]

Thanks.
Here is the .bin for people to pull apart (and hopefully let us know where it needs "tweaking"), and the baby bump stick specs are 220/220 @ 110 degrees LCA with 0.470" valve lift.
Oh, and tri Y extractors through full twin cat exhaust, as that may make a slight difference.
Cheers.

[EagleMark]

Third question: - Is there a "decay time" or a "delay time", or something like that in the program, from on throttle to off throttle? A bit like the old Toyota dashpots that used to hold the revs higher during gear changes for emissions in the early days.

Yes! Very much so to delay snapping back to idle to reduce emmissions but the side effect is easier shift. IAC logic between an auto and manual trans is completly differant.

[The1]

bin is a CNPC3157 you will want to edit it with the $A6 VS V8 Series III xdf

https://pcmhacking.net/forums/viewtopic.php?f=7&t=5

You havn't told us what steps the IAC is at while idling, it just sounds like it's maxed out to me, should be 30 steps at idle.

BTW id fix up that lean cruise table.

[Monarols71]

Thank you.
The IAC steps are in the mid twenties when idling at running temperature. It was exactly the same with the original stepper motor as well, so different IAC motor, same results. Also in this capture, it takes about 3 seconds to settle the idle with no speed or throttle, which is our main concern. About 7.16 to 7.19 I think it's at.
I see what you mean about the lean cruise table. I've tried to import (and manually change) the table from the manual HSV .bin, and it won't keep the changes to our bin. Ive tried zeroing it as well, save it, even rename the saved .bin, but when it's opened again, the -26 or whatever it is is still there. That's using the normal tunerpro. I'll try the RT version later. Even uninstall and reinstall if I don't have any luck.
Thanks