My car is lean going into boost

Supraflymk3

Supraflymk3

Supraman
Dec 17, 2005
272
0
0
37
Neenah, Wisconsin, United States
When I am cruising my AFRS are 14.7 when I decide to step on it when it gets around 0psi it stays at about 14.7 then after about a second or two it all of a sudden goes normal to about 11.3 at full boost. I tested the fuel pressure and its all good. AFM is good. Just installed a new TPS. I don't know what it could be, has anyone ever had this problem or have any ideas that might help me out?

My mods are 7M-GE-T
Driftmotion Intercooler Kit
3" Turboback Exhaust
Apexi Intake
 
dubsupra209

dubsupra209

CENCAL SUPRAS
Mar 6, 2009
1,810
0
36
34
Merced, CA
11.3 is not normal when boosting you should be around 10.4 10.5 10.6 those are all the normal numbers Ive seen for stock 7ms...unless your running a afc to lean it out...?
 
Supraflymk3

Supraflymk3

Supraman
Dec 17, 2005
272
0
0
37
Neenah, Wisconsin, United States
Its GTE electronics. Would someone messing with the adjusting screw in the AFM have anything to do with it?

---------- Post added at 02:13 AM ---------- Previous post was at 02:12 AM ----------

And its not a lag in the time innovate lc1 is very fast you can tell there is a lack of power because when it goes rich it all of a sudden goes alot faster.
 
toyotanos

toyotanos

What will we break today?
Staff member
Super Moderator
Nov 29, 2008
2,841
2
38
Coon Rapids, MN
I have seen fuel pumps running out of flow on 2 GE-T vehicles...usually between 3-4k rpm. The 2 ways I have fixed them would be:
1- Short term fix: is to disable the fuel pump resistor by bypassing it. (Makes the pump run off of 12v all the time)
2- Long-term fix: is to replace the fuel pump with either a GTE unit or an upgraded pump.

Might not be the problem, but it's what I have seen specifically on NA-T vehicles only.
 
Devin LeBlanc

Devin LeBlanc

Banned
Apr 7, 2010
1,830
0
0
32
Las Vegas NV.
I was logging on the LC1 with a laptop and had the same thing happen.. I am tuned for AFR's 11.5-11.7 with the Neo on a dyno but stock should be around 10.3-10.7 with it on a stock computer.. If the AFM screw plug was drilled out and then they loosened the screw all they way out that would lean your mixture out over the whole power band.. Are you just watching the gauge when you see it or are you data logging it on a laptop.. You can't go by the gauge, I would log it and look at the log in LM log works 3

Here is my log on NA-T with no tuning at all stock ECU (GTE) no Neo

p1643610_1.jpg


p1643610_2.jpg


---------- Post added at 12:54 AM ---------- Previous post was at 12:44 AM ----------

Every single time there was a lag when the gauge stayed at 14.7 and then suddenly dropped into the high 10's- 11.0 and stayed under full boost.. But it shows on the graph the smooth drop
 
Supraflymk3

Supraflymk3

Supraman
Dec 17, 2005
272
0
0
37
Neenah, Wisconsin, United States
I know 11.3 isn't bad when I get an SAFC I'll be tuning for 11.7. My AFRS under WOT Full Boost are fine. My cousin tunes WRX's and STi's and I help out alot so I know what good AFRs are. I'm just having trouble figuring out why its doing what its doing.
 
Van

Van

87t Hardtop
Mar 26, 2006
974
0
0
Oak Grove, OR 97267
Devin LeBlanc;1643610 said:
I was logging on the LC1 with a laptop and had the same thing happen.. I am tuned for AFR's 11.5-11.7 with the Neo on a dyno but stock should be around 10.3-10.7 with it on a stock computer.. If the AFM screw plug was drilled out and then they loosened the screw all they way out that would lean your mixture out over the whole power band.. Are you just watching the gauge when you see it or are you data logging it on a laptop.. You can't go by the gauge, I would log it and look at the log in LM log works 3

Here is my log on NA-T with no tuning at all stock ECU (GTE) no Neo

p1643826_1.jpg


p1643826_2.jpg


---------- Post added at 12:54 AM ---------- Previous post was at 12:44 AM ----------

Every single time there was a lag when the gauge stayed at 14.7 and then suddenly dropped into the high 10's- 11.0 and stayed under full boost.. But it shows on the graph the smooth drop
Click to expand...

Hi Devin,
That is imperssive, (the graph of the AFRs on your Supra). I'd love to have those AFRs on my Supra. What are the mods you took to get that result? If you could list them, that would be great. Thanks. Van
 
gottadiesel

gottadiesel

Flyin Low
Feb 16, 2009
459
0
0
Vancouver, Washington
Supraflymk3;1643605 said:
And I said fuel pressure is good. So that's not the problem.
Click to expand...

FYI - Not sure if you actually verified under boost. Fuel pressure at idle is one thing, fuel pressure under boost will be much higher (should be at least 1 psi higher for every 1 psi of boost) I mention this only because my 1st dyno run I started running out of fuel above 14 psi of boost, ended up not only bypassing the fuel pump resistor, but also creating a new 20amp circuit for fuel pump and using the fuel pump relay as pilot duty only and installing new relay to switch the actually 12vdc 20 amp circuit to the fuel pump.

But back to my point, at idle it fuel pressure was at 35psi, at 16 psi it would initially be at almost 70psi, but then at about 4.5k, it would drop back to 40 psi and it would start to go lean... so just verifying that when you say my fuel pressure is ok, when and how is it being read.

Now to the bigger picture, You will get a lot of different advice on this one... What is a safe AFR at WOT, some may have to do with how much boost you are going to run, what is the main goal and purpose of the car (track car or DD). I think it is somewhat consistent for many of the 7mgte guys(oh and gals), especially those running stock internals to tune for 10.8 to 11.2. This is what I have done for mine, but it is also a daily driver that I have put 10k into during the last year... gaining another 30hp and loose more head room on going too lean is not worth it to me... it may be for others. Just my $0.02
 
You must log in or register to reply here.
Top Bottom