Hard starting

Good morning.

I would suspect the fuel pump is losing its prime overnight.

I would start by checking the fuel pressure before starting the engine in the morning. If it is low or 0, replace the fuel pump.

Roy

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

I doubt the relay or a fuse is the issue as it does start and once it does, it stays running all day long.

Check the fuel pressure.

Roy

Removal Procedure

Notice: Numbers in text correspond to numbered components in image.

1. Relieve the fuel system pressure. Refer to Fuel Pressure Release.
2. Drain fuel tank. Refer to Fuel Tank / Service and Repair.
3. Remove fuel tank (3). Refer to Fuel Tank / Service and Repair.
4. Remove the locking nut using J 39348 by turning counterclockwise.

Important: The modular fuel sender assembly may spring up from its position. When removing the modular assembly from the fuel tank, be aware that the reservoir bucket is full of fuel. Tip the modular assembly slightly during removal to avoid damage to the float. Have a shop towel ready to absorb any leakage.

5. Remove modular fuel sender assembly from the fuel tank (4).
6. Remove fuel sender seal (lip). Slide the fuel sender lip seal downward, past the reservoir and carefully over the float arm assembly.
7. Discard the fuel sender lip seal.
8. Carefully discard the reservoir fuel into an approved container.

Installation Procedure
1. Install new lip seal on modular fuel sender assembly. Always use a new lip seal when servicing modular fuel sender unit.

Important: Lip seal should be carefully positioned over the float arm assembly, moved up over the reservoir and half way up the guide posts.

2. Lightly lubricate the inside diameter of the lip seal with engine oil.
3. Install modular fuel sender assembly (4) into the fuel tank (3). Seat lip seal into tank opening.
4. Align arrow on top of the fuel sender cover to arrow on the fuel tank.
5. Slowly apply pressure to the top of the spring loaded sender until the lip seal is flush between the fuel tank and the fuel sender cover. Tighten the locking nut and tighten locking nut to 50 Nm (37 lb ft). Be sure that the lip seal provides a snug seal between the modular unit and the fuel tank.
6. Install the fuel tank. Refer to Fuel Tank / Service and Repair.