2005 Aveo LS hatchback has 80K. Replaced battery and installed new alternator at 80K. Engine cranks but won't start. Have spark at plugs and if i spray starter fluid in intake car runs. replaced timing belt, water pump and fuel pump at 60k. Plugged in my Blue Driver Scan tool and showed no bad sensors in fact everything checked fine. I noticed that my rpm tack didn't move while cranking so i replaced Crank Positing Sensor and needle moved first time i cranked but did nothing after second crank. its getting fuel but I only have 8 psi when cranking. my fuel injectors has 12 volts to one pin but the ground pin is not getting a signal so i have no ground or low to complete the circuit. all fuses and relays have been triple checked and all wiring at all connector including ignition switch have been checked. have no burned wires or shorted connectors anywhere. car was working great until alternator went bad. What am I missing?