Well I have been trying to sort out a lean spot I have been having for quite some time now. Any help with this would help. I may try to get a video up some time soon too.
First my mods.
-Lex AFM
-560cc inj (flow tested)
-AFPR 43psi
-manual boost controller
-3" elbow back exhaust no cat
-57 trim DM ct upgrade
-255 Walbro pump
-SAFC2
I am on the stock IC and piping
Using AEM boost gauge, and wideband
Well here is the deal, at idle 800rpm all through to 6250rpm the car acts normal. The only spot where it is not normal is in the little range from 3400 rpm to 3600 rpm. This makes the car very unstreetable for the little mods that are done to it, because that is right where this turbo starts to spool well.
What it is doing under low throttle (1% to 35% or so) it will drive normal up to around 3300rpm, and just start leaning out, and it will peg my wideband at full lean around 3400rpm, then after 3500-3600rpm it will come back down, and drive normal through the rest of the RPM range.
Under higher throttle (above 35% or so) it will be fine up until around 3300rpm and lean out some as I am coming into boost (13 or 14 AFR), then at 3400 it is at around 16 AFR and around 3500 it will start to come back down to normal (10.5 AFR or so).
The car seems to hold boost fine, I have to run a boost leak test on my car still, but it is running lean not rich, and the lean spot is when the turbo is starting to spool and building boost. So this should not be the problem. Also I did replace some of my old cracked hoses, so there should also be no unmetered air coming in.
So my question to you all is why would my car be doing this? I am thinking it may be the ecu, or the fuel system for some reason.
What I have done to trouble shoot this problem.
-Messed around with the SAFC to add fuel (doesn't help lower AFRs much)
-Added fuel pressure via AFPR (didn't help)
-Turned in the stock lexus AFM tuning screw all the way (lean spot becomes less noticeable but is still there and under low throttle will still lean out all the way)
-tightened, and re-tightened, and rechecked all of my clamps on the stock IC piping (didn't help)
-replaced any split hoses (didn't help)
-took off my SAFC completely (didn't help)
-tightened my MBC all the way (stock boost settings, and didn't help)
-took my MBC off and attached just a regular vacc line (didn't help, just lost power)
The only thing I have not done that I think may solve this problem is to put my stock 440cc injectors back in with the stock MAF and see if that my fix it for now. The only problem is I would have to re wire for the other injector clips again, that is why I have not tried it yet. This is next on my list, and if it solves it I will drive it like that until I can get a standalone.
First my mods.
-Lex AFM
-560cc inj (flow tested)
-AFPR 43psi
-manual boost controller
-3" elbow back exhaust no cat
-57 trim DM ct upgrade
-255 Walbro pump
-SAFC2
I am on the stock IC and piping
Using AEM boost gauge, and wideband
Well here is the deal, at idle 800rpm all through to 6250rpm the car acts normal. The only spot where it is not normal is in the little range from 3400 rpm to 3600 rpm. This makes the car very unstreetable for the little mods that are done to it, because that is right where this turbo starts to spool well.
What it is doing under low throttle (1% to 35% or so) it will drive normal up to around 3300rpm, and just start leaning out, and it will peg my wideband at full lean around 3400rpm, then after 3500-3600rpm it will come back down, and drive normal through the rest of the RPM range.
Under higher throttle (above 35% or so) it will be fine up until around 3300rpm and lean out some as I am coming into boost (13 or 14 AFR), then at 3400 it is at around 16 AFR and around 3500 it will start to come back down to normal (10.5 AFR or so).
The car seems to hold boost fine, I have to run a boost leak test on my car still, but it is running lean not rich, and the lean spot is when the turbo is starting to spool and building boost. So this should not be the problem. Also I did replace some of my old cracked hoses, so there should also be no unmetered air coming in.
So my question to you all is why would my car be doing this? I am thinking it may be the ecu, or the fuel system for some reason.
What I have done to trouble shoot this problem.
-Messed around with the SAFC to add fuel (doesn't help lower AFRs much)
-Added fuel pressure via AFPR (didn't help)
-Turned in the stock lexus AFM tuning screw all the way (lean spot becomes less noticeable but is still there and under low throttle will still lean out all the way)
-tightened, and re-tightened, and rechecked all of my clamps on the stock IC piping (didn't help)
-replaced any split hoses (didn't help)
-took off my SAFC completely (didn't help)
-tightened my MBC all the way (stock boost settings, and didn't help)
-took my MBC off and attached just a regular vacc line (didn't help, just lost power)
The only thing I have not done that I think may solve this problem is to put my stock 440cc injectors back in with the stock MAF and see if that my fix it for now. The only problem is I would have to re wire for the other injector clips again, that is why I have not tried it yet. This is next on my list, and if it solves it I will drive it like that until I can get a standalone.
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