2005 grand caravan 3.8L what is proper resistance for good fuel pump?

Your fuel pressure should be between 48-50psi. I think your combination Fuel Filter/Regulator is clogged. Too much fuel pressure can be just as bad as not enough. You may have more than one issue though. You mentioned that while slowing down or traveling over bumpy roads, the truck "goes dead". This symptom sounds more electrical than mechanical. I might start by looking scanning for codes. See if there is anything in the history or current. A loose or faulty wire, loose or corroded connector, ground or worn component could cause your truck to loose power. This trick doesn't help everyone but it takes a second to find out. If you suspect a faulty TPS, depress the gas pedal .5-1" and try to start the engine. If it starts with it feathered but dies when you release the pedal or wont start with the pedal released. Then take a closer look at that connector and sensor. Please let me know if there is anything else. Good Luck.

Not likely. It is also not likely that the regulator is in the fuel pump assembly. Some people mistake the check valve in the pump as a regulator. Also, some vehicles have a pump module which includes the fuel gauge sensor and that can be mistaken as the regulator by some DIYers. The caravan uses a return-loop fuel system. This means that the pump is cycling fuel from the tank to the fuel rail on one line and the fuel that is not needed at the injectors flows back through another line to the fuel tank. This is done to prevent the pump from building up too much pressure and allows the fuel flowing through the pump to keep it cool. Because of the looping system, there needs to be a flow restrictor (aka regulator) at the fuel rail to provide a constant pressure source for the injectors. The regulator is normally at the end of the rail and will have a vacuum line attached. Pull the vacuum line, place a rag at the vacuum port, and crank the engine. There should be no fuel coming out the port. If any fuel comes out of the vacuum port, the regulator is faulty. The regulator could still be faulty even if there is no fuel from the port, but fuel leakage is an easy way to be sure. If the regulator is not providing proper restriction to maintain pressure, then the fuel simply flows in a circular loop from and back to the fuel tank without enough pressure to allow the injector to do their thing,

Sounds like a clogged fuel filter, a bad fuel pressure regulator, or a failing fuel pump.
Start by replacing the fuel filter.

Could be the fuel pump or pump relay going bad.To check relay simply replace it with another.It also could be the crank sensor or cam sensor.

I had one where the gauge cluster isnt working and van wouldnt start or would start and shut off after 5 seconds so make sure gauges are working

Are you sure that the fuel pump is properly installed? Have you tested the fuel pump circuits to see if they are working properly? Did you also replace your fuel filter? (It could be totally clogged up) Have you checked to see if there is any fuel pressure at the fuel rail or are you just assuming that the pump is not delivering fuel to the injectors? Have you checked your fuel injector circuits for power and for injector pulse from the EngineControl Module? Have you scanned your Engine Control module to see if you possibly have a Crank Sensor or Cam Sensor problem?

The oil pressure switch only keeps the fuel pump running once the engine starts. The fuel pump should run for 2-3 seconds when you turn the ignition switch to the "Run" position to prime the injectors. The oil pressure switch is the problem only if the engine will not continue to run on its own after it starts up.

chec the fuel pump and regulator by gettin car scanned at a parts place--dont just replace parts without proof--car is over 10 yr basic stuf starts wearing out next cud be the water pump or sensors!

If you have good fuel pressure. Check for spark at any plug while cranking, If no spark, also place a screw driver on an injector and listen to it while someone cranks it over. If you have NO spark and NO injector click - crank sensor needs to be replaced. 95%
other 5% hmmm wiring problem on / near crank or cam sensors, theft system active, dead pcm.......

The fuel pressure you listed is to low,
The regulator should keep the pressure down to at least 45psi,removing the vacuum from the regulator it should spike to at least 55-60.
Did it start and run better with the hose off?
replace the fuel filter first,then check the pressure again.

TPS throttle positioning sensor......Located on the throttle body and looks like this pic attached Top pic is TPS and Other is the regulator



Fuel pressure reg 4.3L Engines

1. Properly relieve the fuel system pressure.
2. Disconnect the negative battery cable.
3. Remove the upper intake manifold.
4. Remove the fuel pressure regulator retainer clip.
5. Twist and pull the fuel pressure regulator in order to remove the regulator from the housing using a shop towel to catch any spilled fuel.
6. Remove and discard the regulator seal O-ring.
7. Remove and discard the regulator filter.
8. Remove and discard the regulator seal O-ring.
9. Remove and discard the backup ring.