Lean issue

[monaro308]

Hi all,just a quicky question.
After my LPG mishap and sorting the TP5/plug-in files,I'm noticing that when i take the foot off the acc pedal and rolling up to a set of lights,my AFR's lean out to around 16-17:1 and slowly come back to 14-14.5 and give a rough idle surge until im back to open loop.
This is all happening in closed loop until i see the dash display go back to open loop and then it settles back to 12.8- 13.5:1 @idle to smooth out.
I can sit in Park and do the same symptom.
Am i chasing a VE,DFCO problem or maybe an after issue with a hardware item?
I remember being able to change to length of time when closed loop went into open but haven't had a proper look as of yet with 12P software.
I've always been able to just load the 12P BLCF bin,xdf,adx items and just change my PPK and run the car fine with minor tweaks,but never come across the lean issues i now have when decel or just blipping the throttle.
I'll have a look for any leaks or damage that the blow up may have caused but a quick inspection shows ok so far.
Cheers...mario

[antus]

Sounds like normal enleanment (right term?).. there is enleanment as well as fuel cut off, and it'll happen on decelleration. My gemini leans out to about that on decel and all is good. Does your engine not like it?

[VL400]

Hi all,just a quicky question.
After my LPG mishap and sorting the TP5/plug-in files,I'm noticing that when i take the foot off the acc pedal and rolling up to a set of lights,my AFR's lean out to around 16-17:1 and slowly come back to 14-14.5 and give a rough idle surge until im back to open loop.
This is all happening in closed loop until i see the dash display go back to open loop and then it settles back to 12.8- 13.5:1 @idle to smooth out.
I can sit in Park and do the same symptom.
Am i chasing a VE,DFCO problem or maybe an after issue with a hardware item?

Is this the wideband displaying this or is it the ECU target AFR? If wideband are the BLMs showing that its pulling heaps of fuel?? It sounds like decel enleanment like antus mentioned except if its happening in park or once you have come to a complete stop - should exit DFCO with a extra fuel pulse to smooth things out.

I remember being able to change to length of time when closed loop went into open but haven't had a proper look as of yet with 12P software.

In 12P they are "Idle Fuel Param - Delay before using idle A/F ratio (Auto in P/N)" and "Idle Fuel Param - Delay before using idle A/F ratio(manual & Auto in Drive)"

[monaro308]

VL- Antus,the readings are off my motec AFR meter.
I can just sit in P/N and just give the throttle a small stab and it will return with a rough lean idle until open loop displays on the dash readout(which takes about 20 odd secs to return to o/loop and smooths the idle to the correct AFR)
I don't know whats the average length of time your cars take to return to o/loop but havent had this issue before.
I may have to look into if anything was damaged or popped off.
My DFCO is working as normal when taking the foot off and showing up on the meter,its more when pulling up at the lights it leans out to a rough idle until open loop cuts in.
No changes have been made to the car ,apart from rewelding the plenum and checking for leaks after the welding.
Car does everything fine but now showing the lean closed loop issues in P/N or pulling up to lights.
Your 12P software has been AOK since day 1 but thinking it must be on my side.
I will check the idle fuel param's and see if that fixes my problem
thanks again...mario

[Holden202T]

can you post up a log of this issue ?

[monaro308]

Hi 202,i actually had a look at the idle fuel params as VL recommended when i first started having the issue and noticed the time adjustments in TP were already showing the settings @ 5secs and yet with the car sitting idling and up to temp and stabbing/raising the throttle for closed loop and back to idle it was more like 20 or so secs like i mentioned.This would lean it out when driving and rolling into a corner causing it to almost stall.
I sprayed everthing that i could to find an air leak just to be 100% sure its not hardware..all was good.
So i still felt it was software.
I deleted everything related to TP and loaded an earlier version once again after my plug-in issue and loaded the related 12P files.
Deleted TP again and loaded the latest TP5 build and 12p files and placed the plug-in folder in its right place.
Detected OSE plug-in straight away and hooked it up to the munro.
Rechecked the Idle fuel params again and found the settings in TP @ 20 secs....like the problem its showing.
Adjusted the settings to 5 secs and it works just like it should be.
Idles nice and back to normal,but i haven't driven it yet.
Although i can tell by stabbing the throttle and playing with diff revs and returning to idle it feels good again and going into open loop in the 5 secs as it should.
i'll drive it on the weekend and suss it out.
Maybe the clean install of XP has effected missing files of some sort....i don't know,but it sure has been giving me the shites
as of late.
Luck you guys are a great help...that i do know
cheers...mario

[monaro308]

Reporting back....drove the munro on the weekend and all was back to normal,mixtures at idle and cruising aok.
I'm assuming that doing the clean install of XP has played funny buggers with my cals
cheers...mario