Very lean idle problem
Very lean idle problem My car is running dead lean only at ldle. I searched but couldn't find anyone with the exact same prob. I dont actually tune the car but it is a turbo OFI 6.0L running '00 PCM w/EFILive custom OS and '02 PCM file. Everywhere else the car runs fine but cold start up and when hot its 18-20:1 AFR. Figure there is an adjustment in some table that we've overlooked.
Thanks for any advise.
Chad
Thanks for any advise.
Chad
Originally Posted by SSblack98
My car is running dead lean only at ldle. I searched but couldn't find anyone with the exact same prob. I dont actually tune the car but it is a turbo OFI 6.0L running '00 PCM w/EFILive custom OS and '02 PCM file. Everywhere else the car runs fine but cold start up and when hot its 18-20:1 AFR. Figure there is an adjustment in some table that we've overlooked.
Thanks for any advise.
Chad
Thanks for any advise.
Chad
Originally Posted by Eurospec2
20.1 is free air, pure oxygen, id be looking at what your using to take these readins more then the readings themselves.
A gas engine can idle at 22:1 AFR. Just barely... Not good for it either.
His car was still idling. If the WB was going into % O2 it would have no chance of idling.
60lb injectors but im running 75ish fuel pressure @ full boost so they're more like 75-80lb injectors, runs perfect off idle and, cruising and wide-open. Definitely plenty of fuel available. Running 10.8:1-11.3:1 WOT on 16psi. Soon as you give it the slightest bit of gas at idle the afr comes straight up to 14ish afr. Soons as it idles down after about 5 secs it goes to at least 18.5:1 then flickers to high 19:1 or even just says "LEN" cause I guess it doens't read over 20:1. Idles ok. I am running a PLX wideband that reads damn near exactly the same as my tuners LM1. Drives great, runs strong just don't like idling it that lean.
Never tried that but I will. If it does or doesn't go lean while rolling in neutral what would that tell you?
I also forgot to mention it is tuned SD open loop. But I have been running it like that for 2 1/2 years long before the FI and never seen this problem.
I also forgot to mention it is tuned SD open loop. But I have been running it like that for 2 1/2 years long before the FI and never seen this problem.
Sounds like you are doing what I am and my problem was related to sitting still and the temps increasing while sitting still.
Fortuntantely, many have been down this road. There are people to ask for advice.
Try checking out EFI-Live's forum:
http://forum.efilive.com/
Fortuntantely, many have been down this road. There are people to ask for advice.
Try checking out EFI-Live's forum:
http://forum.efilive.com/
Last edited by 2002_Z28_Six_Speed; Sep 13, 2007 at 12:41 PM.
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Its not IAT related for a number of reasons. The IAT is mounted within a foot of the intercooler outlet and reads almost exactly same as ambient temp while idling doesn't matter for how long. It is down in the lower front bumper so no chance of heat soak. Also, it does this 5-10 secs after cold startup so obviously no heat soak there either. I'll have a look around on the efilive forums though & see what comes up.
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Originally Posted by SSblack98
Its not IAT related for a number of reasons. The IAT is mounted within a foot of the intercooler outlet and reads almost exactly same as ambient temp while idling doesn't matter for how long. It is down in the lower front bumper so no chance of heat soak. Also, it does this 5-10 secs after cold startup so obviously no heat soak there either. I'll have a look around on the efilive forums though & see what comes up.
They said it was my IAT and it doesn't get too high but the AFR goes lean.
Hope you get it figured out.
There are plenty of tables to play with. Decay rate and decay factors under the crank/start folder. Have a look at the additional restart enrichment and the Open Loop ECT commanded fuel multiplier table.
Last edited by 2002_Z28_Six_Speed; Sep 12, 2007 at 09:35 AM.
I am having a similar problem. I am running at 18-21 AFR on startup in open loop. When it goes CL it runs 14-16. I have HPT and I know where to look for afterstart enrichment, just not sure what values to fiddle with. I hope I am not hijacking your thread, I would just like to figure this out too.
Originally Posted by Souless
I am having a similar problem. I am running at 18-21 AFR on startup in open loop. When it goes CL it runs 14-16. I have HPT and I know where to look for afterstart enrichment, just not sure what values to fiddle with. I hope I am not hijacking your thread, I would just like to figure this out too.
Originally Posted by Souless
I am having a similar problem. I am running at 18-21 AFR on startup in open loop. When it goes CL it runs 14-16. I have HPT and I know where to look for afterstart enrichment, just not sure what values to fiddle with. I hope I am not hijacking your thread, I would just like to figure this out too.
A couple of things can screw you up. IAT as sensor heats soaks will drive AFR lean as car sees higher IAT temps. Also might wnat to look for any possible error in your CFOL.
Once you go into CL, is pcm adding fuel or do trims stablize close to 0?
