Car cranks but no start, replaced crank position sensor

Hello everyone,

My vehicle listed above is the GS model. Started having low RPM's during idle and driving slow 2 weeks ago, 400-500 RPM's. It also started stalling while idling and while going slow. My fuel economy also went down about 50 miles on that gas tank. The car was constantly idling low, even while in Park, which was very strange. After a couple days of sitting, it would no longer start anymore, just crank and not catch. So we replaced the fuel pump yesterday, which didn't fix it. Replaced crank shaft position sensor today, which didn't fix it. I have also replaced throttle body position sensor, mass air flow sensor, manifold absolute pressure sensor, idle air control sensor/valve, and cleaned and checked that the cam shaft sensor was working with a multi-meter, and was also getting power. The engine is getting no fuel, the injectors are only getting 5.8V instead of 12V, and the ignition coil is getting no spark. All my research pointed towards the Crank Shaft Position sensor fixing this, especially since it was stalling a low speeds, and now has no spark or fuel injector pulse. The mechanic I've been working with the last 2 days wants to try replacing the Crank Shaft Angle Sensor/Trigger Plate/Crank Shaft Angle Plate, whatever it's called. This is really just a hunch more than anything. We have no OBD2 codes at the moment. We had a P0335 right after replacing the Crank Shaft Position sensor but that went away pretty quickly. My car does seem to throw codes temporarily when I put in new sensors it seems. One other thing I tried was using jumper cables to ground the engine block to the negative battery terminal as someone had suggested with similar issues, but that didn't get it started. Any other suggestions? Also, battery is fine, starter is fine, alternator is fine, no vacuum leaks, does not seem to be engine compression related. So I am totally stuck! Please help!