Where is the fuel injector rail located, in order to hook up pressure guage on '99 Chrysler lhs

To check the fuel pressure on a 2004 Chrysler Pacifica with a 3.5L engine, you will need to locate the fuel pressure test port. This is a small, threaded port that is usually located on the fuel rail. The fuel rail is a metal tube that runs along the top of the engine and supplies fuel to the fuel injectors.
To check the fuel pressure with a fuel pressure gauge, follow these steps:

1. Locate the fuel pressure test port on the fuel rail. It should be a small, circular port with threads on the inside.
2. Attach the fuel pressure gauge to the test port. The gauge will have a hose with a fitting on the end that screws into the test port.
3. Turn the ignition key to the "On" position but do not start the engine.
4. Observe the fuel pressure gauge. The needle should move to indicate the fuel pressure.
5. Compare the fuel pressure reading to the manufacturer's recommended fuel pressure specification for your engine. This information can usually be found in the owner's manual or by contacting the manufacturer.

Then your fuel pump is not working, or your fuel filter is blocked. You will probably have to check your fuel pump circuit if you have no fuel pressure in the fuel rail, where the injectors sit. There is a fuse for the pump, usually in the under hood fuse/relay block. That is probably also where the fuel pump relay is located. You should hear or feel this relay click when the ignition key is cycled from off to on. Also, when the key is turned to on, you should hear the fuel pump in the gas tank turn on for about 2 seconds. This will put the pressure in the gas in the fuel rail, for starting the engine. If you don't hear the pump turn on for that 2 second period, it is probably a bad fuel pump. But know the fuse is good first.

should be on the fuel rail, take the plastic engine cover off and you should see the injector rails on either side of the supercharger, got to be real close to the line towards the firewall

Have you checked base fuel pressure at the injector rail with a gauge ?
The fuel pump or one of the relays may have failed.

Are you sure the injectors are spraying if the pressure is zero ?
Have you checked the fuel pressure regulator ?
Are the spark plugs dry ?

There is a fuel pump in the gas tank that pumps gas up to the fuel rail on the engine going through a fuel filter along the way(usually on the inside of the frame rail drivers side). The sending unit has more to do with telling your fuel guage what level of fuel is in the tank. You also have a fuel pressure regulator before it gets to the injectors that keep the required pressure in the fuel system to make the fuel injectors work optimally. Best thing you can do is get a fuel pressure guage and see what the pressure is up near the motor where there is a fitting on the fuel rail that looks like an overgrown tire air fitting.

Good Luck

what about the starter and altenotor

Have you checked the spark plugs and wires? It could be you have one or more cylinders that are not firing and so the unburned fuel has to go somewhere (out the exhaust).

Sounds like the carb is dirty. I would check that before spending a lot of money of other things.

Do a bleed down test on the fuel pump pressure, hook up the test guage at the injector rail service schrader valve port and run engine for a moment , then turn it off and note the fuel pressure, wait a couple of hours, pressure should not drop more than 5 PSI, if it does replace pump and filter.