The fuel will not go to the engine. The engine will start when adding fuel directley to the carburetor. The pump has been replaced. When I try to start the engine the pump sound only for a short moment, but then stops. The fuse is in good condition as well. Is there anything that I am missing?

I had a 1971 f900 truck , which is a gas engine vehicle, that we used in the harvesting of silage and grain. It had a 534 cid engine and had a mechanical fuel pump which does not require a fuel pump relay. That said, someone could have added an electric pump which could use a relay. Follow the fuel line from the carburetor to the tank. A mechanical pump will be connected to the engine. An electric pump would be inline or in the fuel tank.

Sounds like the float level is too low. I assume your pumping the gas pedal to start. This is where the gas allowing the engine to turn over until it uses up the small amount of fuel you added by pumping.

Are you sure it is a carburetor and not throttle body injection? They do look similar.
If it is a carburetor, there would not be a regulator. The fuel pump will either be a mechanical pump mounted on the engine, or a low volume electric pump in the gas line from gas tank to the engine.
If it is throttle body injection (TBI), yes, there is a fuel pressure regulator, probably located near the throttle body. It will have gas lines connected to it (one line will be a return line back to the gas tank) and a vacuum line. The fuel pressure on TBI systems is not as high as multi point injection, usually around 20 psi. You would have to check the specific pressure requirement for your pathfinder.

Take off the air cleaner cover and look at top of unit. A carburetor should have a choke plate right at top of the carb throat. However some Nissans by '88 had a carburetor without a choke-it used an enricher jet controlled by the ecu for added fuel when starting.. On a TBI, looking down at the unit where the air goes in, you will see one or two injectors with a wiring harness connected to them-each injector will have two wires connected to it.
If still unsure, check engine designation on the under hood label. Carbureted engines will have a s letter designation, injected engines will have letter i. To explain: my '87 Sentra is carbureted, so engine designation is E16s, some same engines were injected, so their designation is E16i.

1st off this car is fuel injected, there is no carburetor. How much gas did you put in the tank? At least 3 gallons is required many times to get the tiny electric fuel pump to not **** air. If adding more gas doesn't get it started you may have burned out the electric fuel pump, the reason is this, the electric fuel pump that is inside the fuel tank depends on the gas it sits and runs in for cooling and lubrication, so when you run out of gas it can and may times does destroy the fuel pump many times, this is even more so true on cars with lots of miles on the pump. You can try adding more fuel and taking a rubber hammer and hitting the bottom of the tank while someone turns the engine over, this may free up the pump, if not then the pump must be replaced, this requires the fuel tank to be removed from the car to gain access to the fuel pump.

If it is fuel injected check for fuel pressure at the fuel rails. If it has a carburetor then try pouring a little gas in the carburetor and see if it will start. If you have no pressure at the fuel rails or the motor starts after adding fuel directly then the problem is the fuel pump.

Carb needs rebuilt, Auto choke not working properly. Be easy on the starting fluid you can easly blow a hole in top of piston.

It sounds like you are experiencing a problem with the Rochester 2GC carburetor on your 1957 Oldsmobile. The issue you described, where the engine is difficult to restart after it has been shut off for a period of time, could be caused by a number of things.
Here are a few things you can try to troubleshoot the problem:

1. Check the fuel level in the carburetor bowl. If the fuel level is too low, the engine may not start. Make sure the fuel level is at the proper level and that the bowl is not leaking.
2. Check the float level. The float in the carburetor controls the fuel level in the bowl. If the float is set too high, it can cause the engine to flood when it is restarted. Adjust the float level according to the carburetor manufacturer's specifications.
3. Check the fuel pump. The fuel pump supplies fuel to the carburetor. If the pump is not working properly, it could cause the engine to flood or not start at all. Test the fuel pump and replace it if necessary.
4. Check the fuel lines. Make sure the fuel lines are not clogged or damaged. Replace any damaged or clogged fuel lines.

I hope these suggestions help! Let me know if you have any other questions.

Does it stay running when you get it started pouring the gas into the intake? If so I would replace the fuel filter or check the fuel line pressure where it goes into your intake.

If it doesn't stay running, I would look at replace the fuel pump.

Good Luck

Do this, take the top off the carb, being careful not to damage the gasket. Then take some carb cleaner and clean out the bowl and floats. Remove the needle valve and clean it out. Put it all back together and filling the bowl with carb cleaner. Start it with the starting fluid. Once you run the carb cleaner through it, it should start to run on it's own. Whatever you do don't shut it off for about 20-30 min unless you have to.

make sure fuel is going to engine from injectors, you can try by adding carburetor cleaner to intake and crak it, if it runs for a little be then ijectors are not firing, some times the ignition module to control the spark will keep the injectors from firing