Lh 2.4 intermitent no signal to injectors

I have an intermitent problem with the lh2.4 injectors
One day it cranks over but cant grab. When checking the diagnostics (3rd stage) the injectors give no life
The next day it starts with no problem

What could be causing the issue?

Specs:
Lh 2.4
Ez-116k
B234f

Check all grounds and connections for pin push out. I always start there when troubleshooting.

Check for spark. Power Stage or Cranks sensor. Injectors won't do anything until the spark happens. ECU provides ground. You should at least have 12V to the hot side of the injectors, if not radio suppression relay would be the next port of call.

-Ryan

Check wiring at relay. Worth swapping it over to the other side and using the fan relay for a while.

Injectors would still fire during OBD test with a spark malfunction.

Also worth cleaning and inspecting inlet manifold grounds as they are for the computer.

Cleaning grounds is always good and you should do it regardless, but the fact you can even get into DTM3 means they're, at least marginally, fine.


If the LED blinks rapildy as it's supposed to, but injectors stay silent, that usually means they're getting ground/trigger, but you can verify that with a test light between an injector connector - negative terminal and battery.

You probably lack injector +, which is usually due to pin-pullout at RSR connector. Or dead RSRelay in the first place. Pull it out and check the pins, are they level and all. If yes, swap the fan relay in, if not fix the connector. If they stay dead, work upstream from there - pull a diagram out and trace continuity all the way.