Suddenly Lean at WOT!
Oct 12, 2009, 12:29 PM
#1
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Suddenly Lean at WOT!
Had the car tuned a few months ago, spiking at 28psi and 11.5-11.7AFR's. Put on a new synapse bov about a month ago since the stocker was leaking. Boost went up to a spike of 30psi but AFR's fell to a pretty steady 11.4-11.5 at wot in a 3rd gear pull. I turned it down a tad and let it be.
Now the car sat for about a week and yesterday I take it for a ride (it's been cold now like less than 35 degrees). Boost spikes to about 30 and AFR's in the 12.5 range! I now have the boost turned all the way back to the 26psi range but it's still in the 12.0-12.1 range which i'm not comfortable with.
I need to hook up the laptop to see if there's any knock, but in the meantime...what could've went wrong??
General power Mods:
Forced Performance RED Turbocharger
Forced Performance Intake Pipe
Perrin Air Filter
Megan Racing 02 Housing
AMS 3" Exhaust
AMS Front Mount Intercooler
AMS Lower Intercooler Piping
AMs Manual Boost Controller
Fujita Upper Intercooler Pipe
Keflford 272 Cams
ARP Headstuds
Buschur Racing Ported Exhaust Manifold
Synapse BOV
Now the car sat for about a week and yesterday I take it for a ride (it's been cold now like less than 35 degrees). Boost spikes to about 30 and AFR's in the 12.5 range! I now have the boost turned all the way back to the 26psi range but it's still in the 12.0-12.1 range which i'm not comfortable with.
I need to hook up the laptop to see if there's any knock, but in the meantime...what could've went wrong??
General power Mods:
Forced Performance RED Turbocharger
Forced Performance Intake Pipe
Perrin Air Filter
Megan Racing 02 Housing
AMS 3" Exhaust
AMS Front Mount Intercooler
AMS Lower Intercooler Piping
AMs Manual Boost Controller
Fujita Upper Intercooler Pipe
Keflford 272 Cams
ARP Headstuds
Buschur Racing Ported Exhaust Manifold
Synapse BOV
Oct 12, 2009, 12:58 PM
#4
just lower your boost by 2psi. Could be due to cold, so you may go over the map. make sure the car is fully warm before you log it. Im around 12 as well, and it was 11.4-5afr at 25psi, but i love how the sucker pulls in cold weather :>
Last edited by tweakdsm; Oct 12, 2009 at 01:06 PM.
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Oct 12, 2009, 03:09 PM
#10
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Checked the FPR lines and there all on and zip-tied. Injectors were scaled for sure.
Well how do I find out if it's hitting different load cells? I have it down all the way to 25 psi and it's still over 12:1. Turning down the boost does not seem to be helping at all anymore....
I mean I know it was tuned for a 28-29 psi spike, so I could just turn up to that, but I don't want to keep doing WOT pulls with the car so lean.
Well how do I find out if it's hitting different load cells? I have it down all the way to 25 psi and it's still over 12:1. Turning down the boost does not seem to be helping at all anymore....
I mean I know it was tuned for a 28-29 psi spike, so I could just turn up to that, but I don't want to keep doing WOT pulls with the car so lean.
Oct 12, 2009, 03:23 PM
#11
Checked the FPR lines and there all on and zip-tied. Injectors were scaled for sure.
Well how do I find out if it's hitting different load cells? I have it down all the way to 25 psi and it's still over 12:1. Turning down the boost does not seem to be helping at all anymore....
I mean I know it was tuned for a 28-29 psi spike, so I could just turn up to that, but I don't want to keep doing WOT pulls with the car so lean.
Well how do I find out if it's hitting different load cells? I have it down all the way to 25 psi and it's still over 12:1. Turning down the boost does not seem to be helping at all anymore....
I mean I know it was tuned for a 28-29 psi spike, so I could just turn up to that, but I don't want to keep doing WOT pulls with the car so lean.
injector can be "scaled for sure" but that doesnt mean their %100 correct. You have to log your fuel trims and see if they drift. If they do, they need work.
Also turning down the boost wont help because fuel tables are usually setup so that more boost(LOAD to be more precise), results in richer AFR and less boost (less LOAD), a leaner AFR.
Oct 12, 2009, 04:40 PM
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Did you log fuel trims???
injector can be "scaled for sure" but that doesnt mean their %100 correct. You have to log your fuel trims and see if they drift. If they do, they need work.
Also turning down the boost wont help because fuel tables are usually setup so that more boost(LOAD to be more precise), results in richer AFR and less boost (less LOAD), a leaner AFR.
injector can be "scaled for sure" but that doesnt mean their %100 correct. You have to log your fuel trims and see if they drift. If they do, they need work.
Also turning down the boost wont help because fuel tables are usually setup so that more boost(LOAD to be more precise), results in richer AFR and less boost (less LOAD), a leaner AFR.
things to check:
vacuum line on fuel pressure regulator
MAF screen intact?
all the hoses on the intake side of the turbo connected properly?
injector duty cycle, if you were close to 100% before, temp getting colder could put you over the limit... i would consider this after the other things above.
Oct 12, 2009, 04:48 PM
#13
Have you replace the intake lately? I had this happen to me when I couldn't find any cone filter to fit my Injen adapter so I bought some K&N and made my own filter. Suck a lot more air causing the lean. I went and got HKS megaflow and it is back at 11.2-11.5. GL Possible boost leak?
Oct 12, 2009, 05:35 PM
#14
LTFT doesn't effect WOT AFR. so once its tuned to 11.5 it wont drift from there assuming everything else is good to go. so that rules out injector scaling as the cause of the lean WOT.
things to check:
vacuum line on fuel pressure regulator
MAF screen intact?
all the hoses on the intake side of the turbo connected properly?
injector duty cycle, if you were close to 100% before, temp getting colder could put you over the limit... i would consider this after the other things above.
things to check:
vacuum line on fuel pressure regulator
MAF screen intact?
all the hoses on the intake side of the turbo connected properly?
injector duty cycle, if you were close to 100% before, temp getting colder could put you over the limit... i would consider this after the other things above.
And +1 on the injector duty cycle.
Last edited by Evo_Jay; Oct 12, 2009 at 05:37 PM.
Oct 12, 2009, 08:44 PM
#15
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I'll check the maf in the morning.
I have lots of counts of knock sum (6-8). I don't actually know how to check the injector duty cycle. Hell I don't honestly what most of the stuff I just logged mean.
If it's it not the MAF screen then i'll just have to take it to a shop that knows what there doing, just sucks living in a smaller town and not having anyone local that works on evo's.
I have lots of counts of knock sum (6-8). I don't actually know how to check the injector duty cycle. Hell I don't honestly what most of the stuff I just logged mean.
If it's it not the MAF screen then i'll just have to take it to a shop that knows what there doing, just sucks living in a smaller town and not having anyone local that works on evo's.