What in the hell has a motor vehicle got to do with a tank water pump?

If you replaced the fuel pump then one of two things probably happened. Recheck the electrical connection on the sending unit or your sending unit was damaged when you replaced the fuel pump. The sending unit is the float/arm device (like a toilet) that sends a resistive signal to your fuel gage. Depending on the vehicle, some failed sending units read full when bad and some read empty when bad. Did you bend the arm of the sending unit when you removed the fuel pump? Did the float happen to stick in a particular spot? The easiest thing is to check your connections at the tank. Most vehicles have two electrical connectors. One for the fuel pump and one for the sending unit. If you are satisfied that the connectors are fine then I would recommend dropping the tank again and inspecting your sending unit. It is virtually impossible to connect the sending unit to the fuel pump cable and vs. versa. Some vehicles have only one electrical connector for both. Sorry but that is the best answer than I can give you.

The short answer is yes.
You would probably have to remove the pump in the tank to keep from trying to pull fuel thru it with the external pump. On some Ford models in the 1980s two pumps were used, one in the tank and one on the frame.

Fuel tank pressure sensor is a sensor that is on my vehicle and I would assume on all vehicles on the fuel tank itself. Fuel tanks build up pressure (lots of pressure sometimes) They must have a way to vent this pressure so manufactures install fuel tank pressure valves and wire a sensor to it and hook it up to the on board computer. On my Mercury marquis it is impossible to replace my sensor without first removing the fuel tank. So to answer your ? yes the fuel pump regulator is different than the fuel tank pressure sensor. If you need help positively locating where it is go to Autozone.com and create an account (free) and enter your yr/mk/model and there you can go to repair help and view online Chiltons repair manuals. Good Luck!

It is impossible to answer your question without knowing the YEAR, MAKE, and MODEL of your vehicle. Please re-post your question, including ALL PERTINENT INFORMAION.

I'm not an expert but it could be the fuel tank that needs a good clean up

It is impossible to answer your question without first knowing the YEAR, MAKE, and MODEL of your vehicle.

Check the feul pump relay

99% of all vehicles made for the last 30 years
have the fuel pump in the fuel tank.!!!!!

Obviously you have to remove the tank,to remove the pump

generally if this vehicle is equipped with a timing chain and gears that would be suspect...the chain/tensioners wearing out...possible water pump bushing but you should see a fan blade wobble or signs of coolant leaking from below...I have seen A/C compressor clutches coming apart that create one hell of a noise before they let loose.... even serpntine belt tensioners can have bearing problems and sound like hell. Good luck hope this helps!! John

Well, obviously someone didn't tell you the truth because spraying into intake doesn't make the vehicle turn over any better. You have ignition or fuel delivery problem. Start by taking fuel line off at intake and crank engine a couple times catching any gas in a cup or something. If none, then trace fuel line back and under vehicle til you find filter. Should be under driverside midway back on inside of frame. Change this and try test again. If no gas, see if fuel pump is on motor(mechanical pump). Change this and test again. If not on motor then it's in gas tank(electric pump). Most cases the tank has to be lowered to take out pump, careful not to drop, dent or make sparks. Some came with access through the floor so check that first. Normally you can hear an electric pump come on when you turn the key. Good Luck