Hi!
I've got a Volvo 360 -90 with a b200f engine.
It has not been in use for over 15 years, and now I am trying to make it run.
I have changed the fuel pump (it was not working) and the pump relay is new, now to my problem the injector will not pulse.
When putting + and - on the injector, it will work, but not when plugged into the socket, (I've got fuel to the injectors)
It gets 12v, but I guess the ground is missing.
Could it be the ICU that is at fault?
The fuse and relay is working.
I read that it gets its ground from the ICU
I guess it is some wire problems because I needed to put new wires to the pump to get it to work.
Can i ground it somewhere else?

I haven't played around with the fuel system on a 300 series as mine never had issues like this. If the injectors are batch fired then the easiest way to tell if it is the wiring is to run a wire from one injector earth to the earth point on the ECU and see if it runs.

Have you checked for an aftermarket alarm system to see if it is blocking the earth signal from the ECU?

Unfortunately no you can't ground them out as the ECU makes and breaks the signal incredibly fast to collapse a magnetic field to make the injectors pulse. I converted a 1991 940 from a B200F to a B230FT and used a 1998 ECU which had an immobilise, I checked everything and found the voltage drop at the injectors wasn't enough so I knew the ECU wasn't sending the right earth signal, I ran a wire from the negative terminal on one injector and tapped it on and off the top mount bolt very quickly and it ran for a few seconds, a new ECU chip with upgrades to the mapping plus the immobiliser removed got it running.