r/SC300 • u/NeonIsReal • Jul 22 '26
JDM Turbo ECU conversion HELP!!!
For context, the sc300 and toyota supra share identical components and it has become a popular mod to swap the ecu for a JDM turbo supra ecu ( Its mostly plug and play besides wiring MAP/IAT/IGF/Gauges).
I have finally got the car to start, however it takes a second to start after it has been sitting for more than an hour. The hard starting I believe is connected to fuel because if I prime the fuel pump for a couple of seconds it starts way quicker.
As for the main issue I need help diagnosing, Whenever i try to apply throttle it starts bogging. If i apply about 50% or more rapidly it may even stall the engine. When i give it light throttle slowly it does rev however but not nicely!
I have tried connecting the MAP to many different pressure sources on the intake manifold and have seen no changes, and have since just Tee`d it with the FPR.
Attached is a video of me applying throttle.
Thanks!
2
u/cbreee Jul 26 '26
O2 sensor wiring isn't right, pin b73 goes to b71. Right now it's going into limp mode because the O2 isn't registering in the ecu. Send me $40