2jz gte swap - running too rich ????

CzA

New Member
Jan 15, 2007
99
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0
Toronto
Hey guys. my friend has an 87 mk3 an di just did a 2jz gte swap in her. he is running rich and i don’t know why.

his wideband shows at idle, 14.8, WOT = 10’s, 100km/h = 14.8. It has intake done with three inch piping, stock twins running around 14 psi, 3inch exhaust, walbro fuel pump, stock 440’s (jdm engine), it has the tpc mod, but its currently disengaged. it will fluctuate from 11.9 to 12.3 at idle. Any ideas why she is running so rich? anything i can look for? thanks...
 

Fletch124

2jz swapped!
Jul 17, 2005
1,282
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Reno, Nevada
14.8AFR at idle and cruise is where your AFRs are supposed to be at. 14.7 AFR is considered stoich; means every oxygen molecule is mixed with every fuel molecule and burned equal with no oxygen or fuel left over. Just about every car i've seen runs in the 10AFR at WOT.
 

Altezza576

New Member
Jul 17, 2009
268
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New York
check your O2 sensor setup.... if you are running the 2JZ ecu, you need the O2 sensor to trim the fuel under boost. I had that problem a few years ago. new O2 sensor helped me out a lot.
 

Brent90turbo

New Member
Jun 2, 2008
9
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Montreal
Altezza576;1421028 said:
check your O2 sensor setup.... if you are running the 2JZ ecu, you need the O2 sensor to trim the fuel under boost. I had that problem a few years ago. new O2 sensor helped me out a lot.

Under boost the ECU should be switching to open loop and running on fuel maps not the 02 sensor.

Your walbro is probably flowing more fuel than originally (I hope!) and the stock FPR cannot keep up. Try a decent aftermarket Adjustable FPR and it should help things out a lot.

On my JDM 2JZ, I decided to swap out the 440s for 550s right away before I installed the motor, forgetting that I was going to be limited by boost cut, the result was like <9:1 AFs under 12psi boost. I got beat by a 1.8T golf on the highway because it was just bogging from being so rich.
 

serpentkilla

New Member
Aug 29, 2009
17
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PA
CzA;1409359 said:
Hey guys. my friend has an 87 mk3 an di just did a 2jz gte swap in her. he is running rich and i don’t know why.

his wideband shows at idle, 14.8, WOT = 10’s, 100km/h = 14.8. It has intake done with three inch piping, stock twins running around 14 psi, 3inch exhaust, walbro fuel pump, stock 440’s (jdm engine), it has the tpc mod, but its currently disengaged. it will fluctuate from 11.9 to 12.3 at idle. Any ideas why she is running so rich? anything i can look for? thanks...


I'm pretty much nunning the same set up and same mods, my car runs great. I thought those numbers were normal.