I have a 93 sc300 with the 2jzgte swap, and I am running lean. the no1 o2 sensor is reading lean, so it is working, i have an aftermarket fuel pump and have done the 12v mod. Everything seems to be working except i am running lean, and cant figure it out. the only modifications i have done performance wise is an intercooler kit, and fuel pump. can someone please help me figure it out, or give me some trouble areas to diagnose
Thank you,
Josh Graham

 

 

how do you know you're running lean? do you have a wideband installed? are you throwing engine codes?

 

I am using an air fuel ratio guage tapped into the o2 sensor wire

 

Im having the same problem. Im not getting any codes but when i pulled my plugs they were as white as the day that i installed them. Im thinking about just buying an apexi fuel controller.

 

thats where im at,

 

I just dont wnt to spend the money, Economy sucks here right now so money is scarce

 

Don't use that narrowband reading to get your A/F. Get a wideband, or go to the dyno for a little bit, just to see where you're at.

 

Really? A narrowband a/f gauge won't tell you anything besides whether the car is in open or closed loop. Throw that thing away and get a wideband o2.

 

I'm with everyone else. Get a wideband ASAP.

 

What ecu are you running and yes get a wideband.

 

the stock 94 supra tt a/t ecu, dyno 50 mi away, any suggestions on an affordable wide band

 

looking over the vaccum diagrams, seems I am missing a vaccum controler right before the fuel pressure regulator, also when i remove vaccum before the fuel pressure reg, it runs rich at idle, and lean in boost, so unless someone says otherwise I am going to assume that missing this piece is not helping my fuel problem. i am also seeing some open vaccum hoses elsware not sure where they go, so i am currently going over my diagrams. I am also using the factory sc300 MAF sensor, not sure if that is causing any problems, but according to my diagrams and my research, the supra uses the o2 sensors to controle air fuel, the MAF is pretty much just there to be there. So please lend me your knowledge!

 

Is the motor us or jdm spec the maf is wrong if us spec jdm uses map sensor.

 

its the jdm aristo motor