Single Point Injection Wiring

ECU has been refurbed and seems to be working fine- better than before anyway!
I've narrowed down my issue to the single point injector.
Spark from the coil, spark on the ignition wire, spark at all four plugs.
Fuel is hitting the throttle body but does not seem to be allowed into the injector area to be mixed and then fired up.
Apparently the ECU sends an injector signal from pin 21 to the injector which allows the fuel in and off we go.

Can anyone tell me where the wiring from the ECU goes so I can trace the signal from the ECU to the injector to see if there is a faulty bit somewhere and is there a voltage I should be looking for at the injector when I turn the ignition on?

Many thanks from across the pond once again!

Gilaguy23 said:

So now that you have a jeep and all its issues you are dealing with, is it really true Rovers are poorly made? Couldn't resist

Click to expand...

100% yes! Haha. Very badly made.
But unlike Jeeps, they were not iconic, not cool, not fun and not worth throwing money at because you love them.
A lot of them went off road but not through choice, though crap brakes and a dodgy suspension

Jaguar Land Rover own Range Rover as a marque. So a RR and LR are different markets but they are both Land Rovers.
In the UK, RR Sport and Vogue are the most stolen vehicles in 2023 and more an more insurance companies are refusing to insure them.

Does anyone have a photo or a diagram of the ECU/ ECM harness or connector so I can see which pin is the one firing a signal to the single injector please? I've been told it's number 21 but don't know which one that is??
1988, 2.5 4cyl SPEFI
Thanks!