Suddenly the engine it will crank but not start up?

Change your fuel filter---

When you turn the key to the on position without cranking the engine over can you hear the fuel pump run in the tank for 5 seconds?

https://www.2carpros.com/articles/car-cranks-but-wont-start

Please run down this guide and report back. scan for codes first see pics for diagnosing

Then do the testing which I sent in last reply

Hello,

This could be from a couple of different things, your vehicle's Profile Ignition Pickup[PIP] or the Idle Air Control valve [IAC]. First let's start with the PIP which the Power-train Control Module [PCM] uses for ignition timing through the SPOUT. In the diagrams down below I have included the description and instructions on how to replace the PIP in your vehicle. Please go through these guides and get back to us with how everything turns out. We can go from there if necessary.

Thanks,
Alex
2CarPros

Good morning.

The fuel pump should only run 2 seconds for priming.

It sounds like you have an issue with the ECM. The scan tools for the old systems did not give a lot of information for diagnostics.

Based on these results, it sounds like you need an ECM.

It is located in the right lower kick panel. I attached a picture for you.

Roy

The Electronic Control Assembly (ECA) stores information about vehicle operating conditions and uses this information to compensate for component tolerances. When an emission related component is replaced, Keep Alive Memory (KAM) should be cleared to erase the information stored by the processor from the original component.

To clear the KAM, disconnect the battery negative terminal for five minutes or more. Drive the the vehicle for at least ten miles to allow the ECA to relearn the values for optimum performance.
NOTE: During the ten mile relearn drive, the vehicle may exhibit some driveability symptoms. These should be eliminated when the KAM has relearned the operating values.