SC400 no injector fire.
 

So before I get hit with the search post. I have searched every single thread from SC to LS. I’ve tried most of what was suggested. I’ve been a member on here long enough to know to read and search the threads completely. And, I am still stumped.

It cranks, and has spark. I’ve test with starter fluid and I have even put direct power to the start injector. The car fires on both but when attempting to start normally it won’t fire. I tested the injectors by a quick ground and they fired. I have swapped ECU to a working one. The pump it on a key on relay because it was not starting with the key turned. I haven’t attempted to ground the anti theft because I still have the trouble locating the specific wire. I just know it’s green but that was on a LS thread. As far as I can tell either something isn’t grounded or the ECU is not getting the signals. I cleaned the crank position sensor and all possible connectors should be connected.

I would appreciate any help with this.


Thank you.

Sounds like you lost connection on the injector circuits
There are many ground points across the back of the engine that are difficult to get to thanks to the wonderful electrical engineers that designed the engine harness to snake all around, on and in the engine and melt from heat (do you detect the sarcasm in my typing?)
Year, mileage, engine series?

95 SC400, 1uz from 93 110k pulled for swap. Motor swapped as the motor in the car was tired. Drifting, road course, etc...

I think your post may have pointed me in the correct direction. The motor was swap but the harness was not connected prior to the motor being in the car. It was placed on after the motor was installed. This causes me to think that the root of my problem is the ground points on the back side of the motor.

All those little grounds on the intake and cyl head are crucial. Either that or there's a break in a wire somewhere imo

If you harness was installed after the motor, you may be in better shape than most IMO
The fcty location of the harness is the absolute WORST place it could have been put
Heat from the engine will destroy the insulation of the wires over time - yours may have been saved
Yes, breaks in the wire are completely possible if it had any heat damage and then jostled around swapping the motor
It would be worth your time to break the harness down to investigate all the ground wires you can find
It was for me as I had to replace 90% of all the wires on the engine to get mine going again
I relocated many of the grounds to easier-to-access points when I relocated the harness off the engine everywhere I could