Not starting after driving for some time

Let's take a step back and see what you are seeing with the plugs.

When you say they are full of carbon, that means they are fouled with fuel. If that is the case, then that will cause this issue but are you replacing the plugs or just cleaning them?

Depending on what we are finding we are going to have to check the fuel pressure to start.

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

This could be a sensor issue causing the air fuel to be off, but we need to start with the fuel pressure and go from there.

Basically, we need to start with the basics so that we are not missing something.

Next thing we need to do is check for codes (you can start with this if you want) and make sure there are no codes.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please run through this info and let's go from there.

Thanks

Thank you Kenny K for responding. The plugs I did replace them but still does the same. When the engine gets hot it starts producing black smoke and idling roughly. If you switch it off it won't start again, all the plugs will be wet. I suspected the TPS sensor because when you start the engine the fan kicks in even If the engine is cold.

This is very possible. Clearly, we know that the issue is the engine is over fueling.

So that means we need to monitor the PCM data with a scan tool just to find out what may be happening.

If the TPS is telling the PCM that the throttle is open when it is not, then it is going to over fuel the engine.

However, I would suggest we start with fuel pressure assuming you don't have a scan tool.

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

Let me know about this and we can go from there.

Thanks