Lean idle with XFI
- Thread starter mzunino
- Start date
How are you monitoring the AFR? Your sig says turbotweak chip, did you just convert to XFI?
A couple things come to mind.
Perhaps the tune is lean, and the closed loop is shutting off. thus revealing the lean condition. Or something is leaning out the engine and the closed loop can't compensate for it. Or your wideband is lying and its not really that lean.
You need to plug into the XFI and see what it thinks the AFR is and what the AFR correction is doing.
Bob
A couple things come to mind.
Perhaps the tune is lean, and the closed loop is shutting off. thus revealing the lean condition. Or something is leaning out the engine and the closed loop can't compensate for it. Or your wideband is lying and its not really that lean.
You need to plug into the XFI and see what it thinks the AFR is and what the AFR correction is doing.
Bob
- Joined
- Aug 1, 2003
XFI aside how is it running . any misses /..shaking . whats the fuel pressure doing... may be a pump going bad ..is there plenty of fuel in the tank so its not sucking air (seeems simple but so are some buick owners)
with 15.9 held steady you may get a wideband fault and SES lamp which will disable closed loop so if you had a tune which needed a lot of positive correction youll lose that added fuel
connect into xfi and and running check for the ecu fault list (display >ecu fault status) look for a check mark on wideband fault
if no check move on to the main VE table
look at AF target vs actual AF and the o2 correction%
if correction maxed (25%) you may have a missing cylinder (spark or injector) or may need more correction ability added in the AF correction table try adding some fuel by increasing the VE table around the bubble cells or just hit L key (save your current gct file first) and see if with the ve up if wideband shows its getting richer .
if acual AF stays lean goto dashboard (view > dashboard) ... post up the uego (V ) ,eugoR (V) and eugo S (V) voltages ..could be your sensor is dead , wiring to sensor damaged or the XFI box is bad
if it gets richer you need to fix the miss or fix the tune
with 15.9 held steady you may get a wideband fault and SES lamp which will disable closed loop so if you had a tune which needed a lot of positive correction youll lose that added fuel
connect into xfi and and running check for the ecu fault list (display >ecu fault status) look for a check mark on wideband fault
if no check move on to the main VE table
look at AF target vs actual AF and the o2 correction%
if correction maxed (25%) you may have a missing cylinder (spark or injector) or may need more correction ability added in the AF correction table try adding some fuel by increasing the VE table around the bubble cells or just hit L key (save your current gct file first) and see if with the ve up if wideband shows its getting richer .
if acual AF stays lean goto dashboard (view > dashboard) ... post up the uego (V ) ,eugoR (V) and eugo S (V) voltages ..could be your sensor is dead , wiring to sensor damaged or the XFI box is bad
if it gets richer you need to fix the miss or fix the tune
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I respectfully disagree because dyno's are also tuning tools and not just outright HP monitors but reliability. I have a longtime friend who owns a shop with a 2w/4w drive dyno and this guy can tune any EMS for daily driver ability and all out HP (been doing it for 40+yrs), he even offers classes for those who want to learn how to tune an EMS. I just think tuners are not being utilized enough in this community and even the Autotune option will be basic and in need of fine tuning on a dyno.
He will be tuning my GN one day.
actually you and I agree.
I was talking about troubleshooting, you were talking about tuning.
If you showed up at your friends shop with a car that's stumbling and stalling, he's going to troubleshoot things before strapping it down.
Bob
I was talking about troubleshooting, you were talking about tuning.
If you showed up at your friends shop with a car that's stumbling and stalling, he's going to troubleshoot things before strapping it down.
Bob
Thank you Bob and you are correct. Troubleshooting starts first before it equals numerous hours on the dyno trying to find a simple problem, sorry for getting ahead of myself....dang car addiction!
turbo nasty
Turbo Dojo / MNTR
- Joined
- Jul 19, 2001
What is your target AFR for low load/idle? How much timing at idle? What is the + # you are seeing on the fuel correction. With the car at idle full ops temp and the XFI connected to laptop hit the space bar and the cursor will highlight the cell being used then hit page up/down to increase/decrease fueling in that cell.
Did you go through the startup procedure? Have you verified your fuel calc parameters are what they should be? Does the target a/f make sense in the problem area? Is it idling in closed or open loop? Is learning enabled? What is the gain in this area?
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Toby_Goodmk
Test Fit officianto
- Joined
- Dec 9, 2011
this goes to prove that you just dont buy an AM management system and throw it in without having someone for support unless experienced in it.. I am glad I went the way i did. Always having someone to help you out. Pay someone for a startup tune after you make sure all the normal trouble shooting stuff is covered. Got to have a startup tune to go with.
haywire4130
Active Member
- Joined
- Sep 11, 2010
Maybe you "fat fingered" a cell on the ve table accidentally or its pulling fuel based on iat or coolant temp if you had those prameters open at some point? It shouldnt randomly go lean for no reason, especially if you had it running good previously. Also, with c-com online and the ve table open, hit g and look for any huge spike looking spots in the 3d graph.
I agree with the post above too, if you added up the amount of time cal has spent on the phone with me vs the meager profit he probably made selling me my xfi, he probably worked for about 15 bucks an hour lol.
I agree with the post above too, if you added up the amount of time cal has spent on the phone with me vs the meager profit he probably made selling me my xfi, he probably worked for about 15 bucks an hour lol.
