Unsteady AFRs at idle and cruise...HELP! - SRT Forums

jtm0n3y · 10-11-2009, 06:53 PM

About three months ago my car ran perfect! It could be sitting in the driveway idling or i could be cruising down the road and no matter what the afr's would be dead on around 14.7 give or take .2....Now it's juming all over the place. It jumps from around 13.1-16 at idle and cruise. WOT is still good however. I CANNOT figure this out. I found an exhaust leak in my o2 housing before i took it off to make a jig for it - that has since been fixed. I replaced all o2 sensors including the one for my innovate wideband. I boost leak tested and fixed a leak that I found between the IM gasket and the head. I checked the o-rings in the injectors...everything has pretty much been looked over and replaced and/or fixed and i'm STILL having the same issue...i'm pretty stumped. What's weird in AFRs are still in check under WOT so that sort of tells me that it's not a problem with my fuel system...what else can I try????

Ragin_SRT · 10-11-2009, 07:01 PM

my idle afrs are the same as you

jtm0n3y · 10-11-2009, 07:20 PM

Did yours used to be right around 14.7 like mine? Like I said mine was damn near perfect then it went to shit and I can't figure out why...need some help and some more ideas of things to try.

ziggo0 · 10-11-2009, 08:03 PM

For the past 2 months my car has wanted to idle no lower than 16.0, bounces between that and 17.9 all the time now. Fuel trims at idle are within +/- 5, I'm clueless as to the problem. WOT AFR's are perfect.

duster360 · 10-11-2009, 08:15 PM

Quote: Originally Posted by jtm0n3y

About three months ago my car ran perfect! It could be sitting in the driveway idling or i could be cruising down the road and no matter what the afr's would be dead on around 14.7 give or take .2....Now it's juming all over the place. It jumps from around 13.1-16 at idle and cruise. WOT is still good however. I CANNOT figure this out. I found an exhaust leak in my o2 housing before i took it off to make a jig for it - that has since been fixed. I replaced all o2 sensors including the one for my innovate wideband. I boost leak tested and fixed a leak that I found between the IM gasket and the head. I checked the o-rings in the injectors...everything has pretty much been looked over and replaced and/or fixed and i'm STILL having the same issue...i'm pretty stumped. What's weird in AFRs are still in check under WOT so that sort of tells me that it's not a problem with my fuel system...what else can I try????

Make a log of your A/F and post it. Include the goofy idle issue and WOT.

Xx_R/T_xX · 10-11-2009, 08:16 PM

mines been at 15.2-15.5 lately,but i have a exhaust manifold leak and o2 housing leak,so i guess thats normal lol

jtm0n3y · 10-11-2009, 09:54 PM

I had an exhaust leak as well...and I though that me fixing it would FOR SURE make the problem go away...like i was so fuckin excited when i found it cause i knew (or though i knew) that sealing that up would bring the afr's back into check...nope...didn't!

How about I make a vid of it..i'll make an idle and cruise vid then a separate WOT vid.

nutz · 10-11-2009, 11:31 PM

could be a million things, what other symptoms does it have ? have you checked the injectors or the ignition system

duster360 · 10-12-2009, 08:10 AM

Quote: Originally Posted by jtm0n3y

I had an exhaust leak as well...and I though that me fixing it would FOR SURE make the problem go away...like i was so fuckin excited when i found it cause i knew (or though i knew) that sealing that up would bring the afr's back into check...nope...didn't!

How about I make a vid of it..i'll make an idle and cruise vid then a separate WOT vid.

No, video suck because gauges suck. just the Innovate up to the pc the make a log. You should be doing this anyway for tuning and resolving issue like this.

Did you remmember to reset you LTFT by dissconnecting the battery, after you fixed all your leaks? Im sure they were all jacked up.

With an exhaust leak and an intake leak, I'm sure the O2 sensor was reading a goofy false lean and causing the PCM add fuel it really shouldn't have. Too much fuel could have fouled a plug. So,,,,,Did you check the plugs?

With a datalog of A/F, you can see igintion missfires(fouled plugs) that will show up as instaneous lean spikes.

Ragin_SRT · 10-12-2009, 09:31 AM

since no one has asked you so, I'm gonna ask you.......are you stock?? oh & even before I upgraded my turbo my afrs were bouncing from 14-15