Nissan pathfinder wont start. fuel pump checks out at 51 psi and spark plugs wet with gas

there are several possible reasons why it would cutout. Problems with fuel pump, ckp or cmp sensors, poor connections. Better have it checked with scan tool.

Could be the solenoid

The fuel pump pressurizes the system and circulates fuel past your fuel injectors. A fuel pressure regulator makes sure there is adequate pressure on the line for the injectors to release the proper amount of fuel when they open (rough explanation). The fuel injectors are controlled by the computer, not really the gas pedal. The computer handles everything for the fuel injection. The gas pedal just opens the throttle plate, allowing more air in. More air needs more fuel, more air and fuel = more power. It all happens very, very fast. Anyway, cranking the vehicle will result in fuel being injected into the cylinders. Without it burning off, yes it could accumulate on the spark plugs and they would appear wet. To work properly, the engine needs (basically) air, fuel, spark, and compression. The timing has to be perfect too.
Look up a quick test on the IPDM ECM relay test. You swap the relay for the computer with one for foglights and test to see if it'll start. That ECM relay has been know to rust internally and fail. Swapping with the foglight relay is merely for testing/troubleshooting purposes. If it works, then you should purchase the proper relay.
There could be many other causes, but this one is pretty easy to try.

Check fuel pressure and for sparks

make sure you have fire at the coil if not there will be no fire to the plugs

have you checked the rotor and distributor cap?

Do you have a timing belt issue?

Fuel pressure for your car should be 50/60 psi you probably need a new fuel pump.

You need to change the fuel pump.

ok, i tell you 3 possible causes.
check maf sensor connection , check fuel pressure regulator (max press fuel in rail 40 psi) , check engine compression (min 95 psi ) if less this cause spark plugs wet and not start