Injector problem

[stuartc44]

I have a vectra c with z22yh engine, beleive it or not I am having some fuel issues. White smoke, strong smell of fuel, mis firing and undrivable but it occasionally clears and runs fine. I beleive I should have a constant voltage to the injectors and the othe side switched to ground. If I'm right, my first question is what voltage should I have? secondly should this be ignition on or engine running or both. And finaly to clarify this is to battery negative?

[Vauxhall Owners Club]

Yes that is correct and the earth pulses the injector
Cannot remember exact voltage but think (distant memory) that it is battery voltage (12 volts upwards)