Losing fuel pressure whrn vehicle sits for two or more hours, 1999 dodge durango. Where is the fuel tank and is the fuel pump replaceable without removing the tank.

May be the problem is not the fuel pump but the regulator valve in the fuel manifold. Has a manifold pressure and pump pressure test been done . One has to be careful with caravans as by nature they sit for long times without use and it is a tendancy to leave the fuel tank with a limited amount of fuel in it with related problems.

Sounds like the pump relay is not working correctly, or you are loosing fuel pressure thru the check valve in the pump.
If the pump runs when you turn the key on, I would check fuel pressure with a gauge before and after trying to start the engine.
The check valve in the pump prevents the pressure from leaking back into the gas tank when the engine is off.

Sounds like fuel pressure is bleeding off. It is not uncommon for this to happen on chrysler vehicles with your style fuel pump module.

The first thing i would do is check fuel pressure with a fuel pressure gauge. The will be a test port on the fuel rail. You should see roughly 50 psi of pressure and it should hold pressure with the key off. If fuel pressure drops the regulator is bad and the fuel pump assembly in the fuel tank will need to be replaced. this will require dropping the fuel tank from the vehicle.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

unfortunetally, if i remember right, on that year the fuel filter is actually on the fuel pump in the tank, and unfortunetally, the only way to get one is to replace the entire pump.

The float mechanism (or fuel level sender) on your fuel pump may be stuck or damaged. Attached is a digram of a typical fuel pump that is located inside the gas tank of your Dodge Durango.
You will need to remove your gas tank and pull out the old fuel pump to see if this is the problem. If you do this I would replace the fuel pump with a new one.

you will need to drop the tank after you release the pressure from the tank and empty it, the fuel pump is in the top of the tank, be very careful with everything you do being any spark or any flame (if you smoke) will explode the tank and cause a bad fire. you should make sure before you put the tank back together after you work on it, that the gaskets are all ok and not torn or broken.

don't guess the fuel pump is $300.00, when it quits check the fuel pressure or listen for the whine of the pump in the tank, it is my opinion u most likely have a loss of spark problem, have autozone or kragen auto run a trouble code test, if nothing shows u may have a fuel problem. The test is free.

Replace the fuel pressure regulator in the intake plenum. This is the No. 1 problem for hard starting with the 4.3 L engine. It leaks fuel and loses fuel pressure when sitting for a few hours. You can try to cycle starter for a split second without cranking wait 3 seconds the turn key OFF then repete 3 times then tryto start. This will build up lossed fuel pressure and verify leaky fuel pressure regulator. Joe ASE Master Tech

change the fuel pump its bad

The fuel filter is part of the fuel pump module in the gas tank, the filter is attached to the top of the module and is replaceable, cost for the filter unit is $45.00, bad news you will need to drop the fuel tank to get to it.