Notices

Lean under boost!!

Thread Tools
 
Search this Thread
 
Old Oct 28, 2008 | 12:42 AM
  #1  
Complink's Avatar
Thread Starter
Evolving Member
 
Joined: Feb 2007
Posts: 207
Likes: 0
From: Lake Charles, LA
Lean under boost!!

ok so i am having a problem with my fuel. i have tried just about every thing except checking the fuel pressure (don't have a gauge). When i first installed my 16g with stock injectors and ecu tuning, it would lean out bad like 17-19 afr at like 4 or 5 psi. then i put in a 12:1 fmu still on stock injectors and my fuel table's maxed out in ecuflash, and it would still come close to 13.5 or 14 afr at around 8 psi. Then i put in wrx 440s, scaled and tuned the trims and removed the reference line on fmu and its even worse. then i reconnected the reference line and tuned my trims and it wasn't much better than the stockers. at this point i was thinking it must be my TRE fuel pump so i got a walbro 255 HP and took off the reference line and its still hitting like 18 afr at wot at prob less than 5 psi. keep in mind my fuel maps in ecuflash are maxed out. I also noticed on a few of my old logs with stocker injectors and fmu my IDC wouldn't go past 64%. So i don't know if maybe my maf is the one to blame. i may have to fiddle with my maf scaling, but not quite sure how to do that.... Any suggestions?

i'd really rather not hook the fmu back up since this potentially causes the fuel pressure to go up to 120+ psi
Reply
Old Oct 28, 2008 | 07:41 AM
  #2  
TouringBubble's Avatar
Evolved Member
iTrader: (2)
 
Joined: Jul 2006
Posts: 2,639
Likes: 3
From: Chelsea, AL
Can you post a pic of your fuel map? Aslo, are you editing the high or low octane map?
Reply
Old Oct 28, 2008 | 09:17 AM
  #3  
Complink's Avatar
Thread Starter
Evolving Member
 
Joined: Feb 2007
Posts: 207
Likes: 0
From: Lake Charles, LA
i'm doing both cuz i remember something about the only one used is the low, so i do both to be sure.

oh and im auto btw.

Last edited by Complink; Oct 28, 2008 at 09:28 AM.
Reply
Old Oct 28, 2008 | 09:19 AM
  #4  
Complink's Avatar
Thread Starter
Evolving Member
 
Joined: Feb 2007
Posts: 207
Likes: 0
From: Lake Charles, LA
i will see about getting a log file if that will help
Reply
Old Oct 28, 2008 | 09:21 AM
  #5  
ambystom01's Avatar
Evolved Member
iTrader: (7)
 
Joined: Sep 2003
Posts: 15,634
Likes: 75
From: Canuckistan
Could it be that you're not reacting fast enough, ie. the car hits boost and thus leans out before the extra fuel is added?
Reply
Old Oct 28, 2008 | 09:33 AM
  #6  
Complink's Avatar
Thread Starter
Evolving Member
 
Joined: Feb 2007
Posts: 207
Likes: 0
From: Lake Charles, LA
well when im going about 45 and i punch it, my rpms jump to about 4 to 4.5 k and almost instantly its leaned out past 17 or 18 at near 8 psi. so i let off. im auto btw
Reply
Old Oct 28, 2008 | 09:36 AM
  #7  
Complink's Avatar
Thread Starter
Evolving Member
 
Joined: Feb 2007
Posts: 207
Likes: 0
From: Lake Charles, LA
at wot i won't start getting boost till about 3200rpm... then full boost comes about3.8 to 4k
Reply
Old Oct 28, 2008 | 09:40 AM
  #8  
ambystom01's Avatar
Evolved Member
iTrader: (7)
 
Joined: Sep 2003
Posts: 15,634
Likes: 75
From: Canuckistan
Sounds like a problem going from closed loop to open loop.
Reply
Old Oct 28, 2008 | 10:06 AM
  #9  
TouringBubble's Avatar
Evolved Member
iTrader: (2)
 
Joined: Jul 2006
Posts: 2,639
Likes: 3
From: Chelsea, AL
Could be Amby ... you could try reducing the values in the Open Loop Throttle table for earlier onset of open loop.

Does the car act like it's lean? Are the plugs reading lean? Everything looks fine with the map ... maybe you have an exhaust leak or a bad sensor?

Yes, logs will help. Please include the stock O2 as well as the WB.
Reply
Old Oct 28, 2008 | 10:48 AM
  #10  
Complink's Avatar
Thread Starter
Evolving Member
 
Joined: Feb 2007
Posts: 207
Likes: 0
From: Lake Charles, LA
when its leaner than 16 it hesitates so yeah.
Reply
Old Oct 28, 2008 | 10:57 AM
  #11  
TouringBubble's Avatar
Evolved Member
iTrader: (2)
 
Joined: Jul 2006
Posts: 2,639
Likes: 3
From: Chelsea, AL
What AFR are you reading in closed loop ... steady cruise?
Reply
Old Oct 28, 2008 | 10:59 AM
  #12  
Complink's Avatar
Thread Starter
Evolving Member
 
Joined: Feb 2007
Posts: 207
Likes: 0
From: Lake Charles, LA
well the only things i can think of thats wrong are:

1. bad fpr
2. clogged fuel lines
3. ecuflash problem

tommorrow im gonna go pickup a fp tester and see what my pressures look like

is it possible that my ecuflash is not flashing correctly? the rom info is:

lancer oz 5mt 03, ecu idblank), case idblank), internal id: 81900016, flash method: mitsukernel, memory module: sh7052, checksum module: (blank), inherits: 81900006
Reply
Old Oct 28, 2008 | 11:00 AM
  #13  
Complink's Avatar
Thread Starter
Evolving Member
 
Joined: Feb 2007
Posts: 207
Likes: 0
From: Lake Charles, LA
Originally Posted by TouringBubble
What AFR are you reading in closed loop ... steady cruise?
it reads 14.7
Reply
Old Oct 28, 2008 | 11:07 AM
  #14  
TouringBubble's Avatar
Evolved Member
iTrader: (2)
 
Joined: Jul 2006
Posts: 2,639
Likes: 3
From: Chelsea, AL
are the trims in check?

A test would be to slowly roll on to the throttle to 100%. If the issue is in the maps and related to open loop, you'll see the jump in AFR instantly when the crossover occurs.
Reply
Old Oct 28, 2008 | 12:20 PM
  #15  
Complink's Avatar
Thread Starter
Evolving Member
 
Joined: Feb 2007
Posts: 207
Likes: 0
From: Lake Charles, LA
ok so i have some logs. and don't mind the trims since it would do the same thing when i had them zeroed and the injectors scaled correctly.
Attached Files
Reply



All times are GMT -7. The time now is 10:26 PM.