1JZ lean at WOT

[jzxseven]

Hey everyone, I'm pretty stumped as to why my motor is running leaner than is should be at WOT.

Background info:
I was running an Aristo 2jzgte ecu before I switched to a JZX90 Chaser 1JZ ecu and it was running perfect.

Now I'm running a 1JZ Chaser ecu and it was running fine and AFR were fine at idle, cruising and WOT.

I reset the ECU and now WOT AFR is in the 12's.
Idle and cruising AFR are fine.

Mods:
FMIC w/ 3 inch piping
Ebay y-pipe with 3 inch exhaust all the way back
PLX wideband
MKIV Supra OEM fuel pump

 

[mensrea]

12 is not lean at all, or am I wrong?

 

[suprahero]

12 is not lean at all, or am I wrong?

He said in the twelves. That is too lean for wot.

jzx.. why did you switch ecu's if it was running perfect before?

 

[jzxseven]

Ecu wasn't mine. So nobody has any suggestions?

He said in the twelves. That is too lean for wot.

jzx.. why did you switch ecu's if it was running perfect before?

 

[86_sports_1jz]

sounds normal to me but it could be that the aristo ecu ran rich because its running a fuel map for a 3.0 instead of a 2.5 liter. meaning it adds more fuel then a 1jz ecu, thats why when you switched to the 1j ecu it ran lean cuz its dumping less fuel than before. hope that makes since

 

[mensrea]

He said in the twelves. That is too lean for wot.

jzx.. why did you switch ecu's if it was running perfect before?

Too lean? 11.5 ~ 12.4 is pretty damn good for WOT.
it's not really lean until you start getting into low-mid 13's+

 

[S.A. supra]

I run it that range at wot. 11-12.5

 

[RockPaperSwoRD]

raise your fuel pressure a few psi, if you dont have a fuel pressure regulator, get one next