Lean under boost!!
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
i'd really rather not hook the fmu back up since this potentially causes the fuel pressure to go up to 120+ psi
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.

oh and im auto btw.
Last edited by Complink; Oct 28, 2008 at 09:28 AM.
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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.
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.
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 id
blank), case id
blank), internal id: 81900016, flash method: mitsukernel, memory module: sh7052, checksum module: (blank), inherits: 81900006
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 id
blank), case id
blank), internal id: 81900016, flash method: mitsukernel, memory module: sh7052, checksum module: (blank), inherits: 81900006
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.
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.


