I have a 2002 Nissan Sentra GXE 1.8L. About 4 or 5 months ago, my car wouldn't start up. The engine would turn over, but wouldn't start. I had a local mechanic come tow it to his place. He thought it was my fuel pump, but when he ran the diagnostic check, it wasn't. My spark plugs were replaced and my 02 sensors were replaced. Now, this morning I go to crank it and it won't start. So is it the fuel pump this time? I tried jumping it off, thinking maybe my battery was getting low, but it still won't start up. Please help me figure out what is wrong with it.
Thanks

. Test all under dash and under hood fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-t...tml#post252145

Be very thorough, since it will save a lot of time and money.

. Check for codes.

. Test/replace the crankshaft position sensor.

If you can hear the fuel pump run, when the ignition switch is turned to ON, it is likely fine. Modern-day electrical fuel pumps are very reliable. If the fuses are fine and there are no codes, I would focus on the Crankshaft Position Sensor. Because of their location and exposure to the elements, they are prone to fail. It's best not to jump modern-day cars. Voltage spikes can destroy ECMs, alternators, and sensors. There's no need to ask for big-time trouble. It's best to remove and fully charge the battery, which most auto parts stores will do for free.