Fuel Injector Issue on a 1990 Pontiac Sunbird 2.0 engine with a single fuel injection system. Getting fuel, voltage to injector but no pulsing of the injector. Changed computer, chip and relays. Getting 12 V on plug, this should, should be around 3.5 V or so ? Pressure good. When i put an injector testerr I do get a pulce and can start the car. Any ideas?