Car cranks but does not start fuel pump runs and sometimes it does not.

More than likely the fuel pump is failing and even though it is running, it is not able to supply the proper pressure.

So that means we need to start with checking the pressure of the fuel system.

Please run through this guide and let us know what you find with this.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

If the pressure is okay, then we need to check the fuel pump relay. Here are a couple guides that will help with this:

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

I suspect the relay is failing which causes the pump to run intermittently. However, if the pump is running but the engine still is not running then we need to suspect the pump has failed.

Please let us know what you find with this. Thanks