I may be a little slow, but I can't understand how the heck the simple old L jetronic ECU gets an ignition reference to start and to maintain injector pulse.
Seems to have something to do with the control rly. yet according to ECU pinouts, there is no pin on the ECU dedicated to ignition reference, and no wire from ECU to coil or relay.
I have a speedway sedan with XE jetronic L system and control relay wired in exactly as if it were in a normal car. The injector pulse simply doesnt happen at cranking. I get one pulse as the starter button is released, and the starter and coil circuits are wired correctly (checked quite a few times)
The control rly is new, there is good fat spark off the coil and the pump operation seems to be normal.

Does the tach connector at the ECU need to be connected to a tacho?
Seems more like a tach OUTPUT to me

I'm sure the answer is obvious, but damned if I can see it.

I found the problem.

After much research I discovered that most L jetronic systems use ECU pin 1 for ignition reference.
I then noticed (dunno why I didn't see it before) that pin 1 on this XE system was used for the tach wire, which I had assumed was for a TACH - OUTPUT.
Not neccessarily so it seems, because once connected to the coil negative it all came good.

Ahh . . . . Mods can be such fun.