Injectors not working

[ryn004]

I'm just finalizing an engine rebuild and the car tries to crank but does not start. Went through lots of potential things that could have gone wrong and since the injectors are not spraying fuel but there is a spark we are thinking that the culprit is the ECU not sending the signal to the injectors.

I have done some research and see that Pin #1 on the ECU connects directly to the negative terminal of the ignition coil, which does not seem to be the case in my situation. Can I safely reroute a fresh wire or should there be a resistor in between?

[JSM]

Need more details, like Year of car, definition of what was replaced in engine rebuild. 

I woukd not be in a hurry to circumvent the stock harness if it was prior working. You’ll introduce more problems in my opinion. Did you go through this. 

[Zed Head]

The details that JSM asks for would help.  Plus a bunch of others, like how long have you had the car, did it run before, why did you rebuild it, etc.  But, your finding that the coil neg needs to go to Pin 1 puts you ahead of many (no offense to many).

The wire to the ECU should already be there, in the engine bay.  There is no need at all to remove it.  It's blue.  It's also connected to your tach.

Don't overlook that the injector power is on its own circuit.  The ECU doesn't "signal" the injectors, it just provides a ground so that the power can pass through them.

Here's another link to the book JSM tried to.

 

[ryn004]

The problem has been solved, indeed it was a disconnected wire from the ignition coil. Might have become loose while we took the engine out to replace all gaskets.

However to provide a solution to future viewers, let me share some more information. My car is a 1976 RHD 260Z with a L20 ET engine. I came to the above solution after reading page 61 of the EFI bible. Yes  Pin #1 on the ECU connects directly to the negative terminal of the ignition coil.

 

[JSM]

Awesome!