Another beginner needs help. Idle / rpm hang issues

[SirNemesis]

I finished work early today so I took the car out for a spin. Log file attached. You can see that it doesn't like driving when cold at all. RPM's drop way too fast and it stalls. When warm it was better, idle hanging for a while, then perfect, then stalling again. Me pulling into the driveway at the end of the log was another stall.

Sir:

I realize you have your MAF physically removed. But, check out this thread about MAF DTC's. Without one present, you will still be using the MAF Table..http://forum.efilive.com/showthread....l=1#post119580

Granted, sometimes DTC's will not be stored in the log (BBL according to 5.7ute). So here is the easiest way to check. In Table C6001 change P001-P003 to A: 1 Trip, Emissions Related. In Table C6002 change P001-P003 to MIL.

You should see the MIL 'light-up'. Then log.

I would hate to see you go tho all this trouble, and find your airflow and fueling was all coming from the MAF. That would obviously effect your Idle.

Like I said, your tune is complicated..but that is an easy sanity check..

Thanks WeathermanShawn. I've made the suggested adjustments, but I haven't flashed in the adjusted tune yet. I'll do it tonight.

SirNemesis, I had the same issues as you shooting for 60-80 steps at warm idle where there wasnt enough airflow at a cold start at 310 steps. I found leaning out the mixture at idle to help, along with some major work in getting the base idle solid.
What you could also do is open up the IAC passage in small increments, being careful not to damage the pintles seat but this would be a last resort.

Thanks for that 5.7ute. The car does smell very rich on cold start, and dark puffs of smoke are visible out of the exhaust. {B3632} was reduced by another tuner to compensate for this, and it did help with cold starts. Prior to this change it wouldn't start at all without throttle assistance. Perhaps the mixture is still too rich, even though the wideband doesn't seem to show this? I've heard that overly rich mixtures are read as lean by some wideband sensors.

[WeathermanShawn]

Wideband AFR shows pretty rich. Why are you running it so rich at Idle? It appears like your AFRBENS are indicating your VE Table needs some work (or your MAF Tables are still engaged). My car would not run good with those AFR's at Idle, especially cold. It gets leaner as you warm up. Might explain a lot.

Still no MAF DTC in your log..

[joecar]

Edit->Properties->Logging->Autosave metadata and checkmark DTC's.

[5.7ute]

SirNemesis. Looking at that last log you were having stalling issues which IMO appears timing related as your spark is very unstable coming to a stop. Whereas the iac steps are stable which shows it isnt an airflow table decaying too fast. I will have a look through your tune file later today to see if I can come up with any suggestions.

[SirNemesis]

SirNemesis. Looking at that last log you were having stalling issues which IMO appears timing related as your spark is very unstable coming to a stop. Whereas the iac steps are stable which shows it isnt an airflow table decaying too fast. I will have a look through your tune file later today to see if I can come up with any suggestions.

Thanks for that 5.7ute. Just a thought with the missing MAF DTC's, would this be because I'm using BBL?

[5.7ute]

Yes. Joecar's post I believe is how you get BBL to log the DTC's, but I am not 100% on that.

[joecar]

It seems to me that BBL does not record DTC's... if you have a V2 you can save all diagnostics to file.

[Frog]

Hi Jocar, enjoy your contributions to the guys fighting with their tune issues. My c5 with ls7 m6 has idle swing pulling into parking lots, or trying to manuver,and parking . Have efi/road runner .Another question, the IAC effective area table, do you recalibriate this table for the bigger engine 427,lastly the scalar # stock 0.0255 currently is set at 0.0310. Really would like some one of your ability to check my tune /vehicle, I'm in Fullerton, Orange county . thread 4661 is something I will be reading over a few times, is there a thread like this ETC drive by wire specific. Cheers ,frog

[joecar]

Hi Jocar, enjoy your contributions to the guys fighting with their tune issues. My c5 with ls7 m6 has idle swing pulling into parking lots, or trying to manuver,and parking . Have efi/road runner .Another question, the IAC effective area table, do you recalibriate this table for the bigger engine 427,lastly the scalar # stock 0.0255 currently is set at 0.0310. Really would like some one of your ability to check my tune /vehicle, I'm in Fullerton, Orange county . thread 4661 is something I will be reading over a few times, is there a thread like this ETC drive by wire specific. Cheers ,frog

Post your tune file...

we'll work thru idling tuning together.



I'm in GG, 1 mile north of the 405/22 interchange.

[Frog]

Thank you for your response Jocar, very ready to post my tune..........but not able to find "attach file" here??