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?