So I'm thinking that it's the fuel pump

I am attaching the process from the USA version of the Lancer. They did not offer the Lancer in the USA in this year so we don't have that specific vehicle but the Galant was basically the same vehicle. You are correct that this is removed from under the vehicle.

As for the issue, I am not sure this is a pump issue. If it is running like that with all that blue/white smoke I think you have other issues.

I would start with checking the fuel pressure before you replace the pump.

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

Once we know what the pressure is we can determine the next steps. However, I would start with checking the compression and going from there.

https://www.2carpros.com/articles/how-to-test-engine-compression

Let us know and we can go from there. Thanks

Okay. I am not sure this is the issue because how is the vehicle running if you don't have fuel going through to the cylinders? If the vehicle is running but running poorly then you have spark and fuel but maybe they are weak but again, if the engine is running then you have fuel.

Maybe I am not understanding the issue so let us know what we are missing. Thanks

Okay. So just to be clear the vehicle is only running if you are adding fuel to the intake? If that is the case then I am in agreement that you have a delivery issue. So if you have proper pressure we need to check the injectors with a noid light or test light. However, have we confirmed the pressure is correct? I am not seeing that it was or maybe I just missed that.

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

Let us know this info and we can go from there. Thanks

https://www.2carpros.com/articles/how-to-test-a-fuel-injector