this is my first na-t build and although i have some good guys around me with na-t sc 300 we are all stumped on this one


since pulling motor out and doing everything req to go na-t ( headgasket,oil lines etc etc) and converting over to r154 5sp, we have reinstalled motor car starts up fine , one crank and it running everytime

however its dumping tons of fuel and i mean tons of black smoke

i am using rx7 550 injectors that drop into fuel rail with the square tops so they plug right in.. i bought the na-t kit used with the injectors but i negelcted to have them sent for flow testing or even cleaned


i have since installed the 2 o2 sensors into the down pipe ( this is a 97 sc300 so its OBDII) to try and keep ecu happy although the rear mounted o2 i have yet to put into midpipe

so question is in your guys best opinions why do you think car is dumping so much fuel

could it be leaking or dripping or stuck open injector/s

could it be the last o2 sensor not being installed so ecu does not know what to do

could it be egr valve ( now we have removed all egr related stuff and have installed egr block off plates)

bad pcv valve

i am using map ecu v3 and even when i zero out all tables the injectors still dump fuel , no change in bahavior so i know its something with oem stuffor the injectors themselves


any help with be much appreciated for i really want this car on the road already

thanks guys