Fuel pump?

See attached

Sounds like the computer is not grounding the relay or its not powering the relay

If you just right click on the diagram and save it to your drive, you can print it from there.

If you can activate the pump from your scan tool, that proves the circuit is fine and the computer has control of it. There may be a problem in the way you are testing because it only powers for 2 seconds or there may be a problem with the ASD relay.

It's G303

I assume you meant the ground for the pump itself, not the relay. The PCM grounds the relay to turn the pump on.

The fuel pump gets turned on for one second when you turn on the ignition switch, then again whenever the engine is rotating, (cranking or running). If you can hear it running during cranking, the pump should be okay.

That one second is usually enough time for it to build close to normal fuel pressure of around 45 - 50 psi. Start by checking that pressure. There will either be a test port on the fuel rail on the engine, or you'll need to insert an adapter "tee" in the fuel supply hose where it crosses from the body to the engine.

You can also use a scanner to command the Engine Computer to cycle the fuel pump on and off about once per second. An alternative is to remove the fuel pump relay, (or automatic shutdown, "ASD" relay), then bypass it with a stretched-out paper clip or piece of wire. Use terminals 30 and 87 for this purpose. That way you can see if the pump runs without having to crank the engine or even turn the ignition switch on.

Chrysler fuel filters for gas engines usually last the life of the vehicle, so that will be way at the end of the list of suspects. You should find fuel spraying from the filter when a hose is loosened, due to the residual fuel pressure in the line, but that doesn't tell you if that pressure was high enough for fuel to spray from the injectors. If you get just a little trickle of gas from the filter, the best suspect is the strainer on the end of the fuel pick-up hose in the gas tank is collapsed or plugged. That strainer is available separately for most models, and costs around $12.00. The most common symptom when these become plugged is the engine runs fine at highway speed for as much as 15 miles, then the engine stalls when the highest volume of fuel is being pumped, which is during coasting.

What is the symptom or problem you're trying to solve?

Let me know what you find, then we'll figure out where to go next.

The starter solenoid is usually on the same circuit. A faulty starter is often the problem. The fuel pump itself may be the culprit as well.

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There's two ways to replace the fuel pump. One is with an entire housing assembly with the fuel level sending unit attached. The other is to take that housing apart and just put in a new pump and motor.

A lot of new pumps come with a new filter sock that has to be clipped onto the bottom of the housing, but if yours did not, that is a good suspect. The common symptom is a little different than what you described, but we still have to consider it. Chrysler's external fuel filters will rarely solve a problem except with diesel engines. They commonly last the life of the vehicle, unless they rust out and start to leak.

There's three things to consider when you can hear the fuel pump running, but you're not getting any fuel. The first is the two hoses are switched. These are different sizes on my old rusty trusty '88 Grand Caravan, yet, by not paying attention, I was able to switch them when reinstalling the gas tank. As if that wasn't bad enough, years later I did that a second time.

The second problem has to do with that strainer clipped to the fuel pump housing. With high mileage, those will become plugged or will collapse and cause stalling, commonly after driving ten to fifteen miles. The glaring clue in this case, with vehicles that have a fuel pressure regulator on the fuel rail on the engine, and a return line to the tank, is the engine will run fine at highway speed, then will stall when the highest volume of fuel is being pumped, which is during coasting. The way you're testing for fuel, you should be seeing at least something being pumped, even if the strainer is plugged.

The third potential problem really threw me for a loop the first time it occurred. The fuel pump strainer sits in a bowl in the center of the tank. That's so the gas doesn't run away from the pick-up tube when you go around a corner. After replacing the fuel pump on my '88 Grand Caravan, when you pour gas into the tank, it drops right into that bowl. All it takes is less than a quart to get it started. That is not the case with my '94 Grand Voyager. The filler tube misses that bowl, so you have to pour in a minimum of five gallons of gas before it gets high enough to spill over into the bowl where it can reach the pick-up strainer. Once the pump starts pumping gas, fuel returning in the return line washes into that bowl and siphons gas from the tank along with it into the bowl to keep it full, so you can run it well below that five-gallon level. You just need the five gallons at first to get the engine started.

Just saw your second post. I suspect that last thing I described was the issue. Once the pump starts moving fuel, that air will be out of the lines in a couple of seconds, even if they were completely void of fuel.

Let me elaborate on that bowl in the tank. The pump is able to pump one to three gallons of gas per minute; way more than the engine will ever need. The gas in the line has to reach a high enough pressure to push open the spring-loaded pressure regulator, then that gas goes right back into the tank where it keeps the bowl full. That restriction limits the volume a little, but there will still be a good gallon per minute being circulated. Only a very tiny fraction of that gas will be tapped off to go through the injectors into the engine.

Now think of the molecule of gas sitting in the injector, just waiting to pass the valve in the nozzle. There's two forces acting on it. One is the fuel pressure pushing on it and the other is intake manifold vacuum pulling on it. The Engine Computer knows manifold vacuum from the MAP sensor, and it is programmed to know what fuel pressure should be. Based on those two things, it has a starting point for calculating fuel needs. During coasting, especially coasting down from highway speeds, manifold vacuum goes way up. That increases that force acting on the molecule of gas, and that would result in an excessively-rich mixture and very high emissions. To prevent that, there's a vacuum hose connected to the pressure regulator. That vacuum helps pull the regulator's valve open easier, so fuel pressure drops a corresponding amount. Vacuum pulls harder on the molecule of gas, and fuel pressure pushes less. The net difference between the two forces stays the same. If you were to drive with a fuel pressure gauge attached and clipped under the wiper arm so you could watch it, as I have done multiple times, you'd actually see that pressure go up during acceleration, and drop during coasting.

The point of this sad story is during coasting when fuel pressure drops significantly, it is much easier for the gas to push through the regulator and go back to the tank. With less restriction imposed by that valve, volume goes way up. That is when you can't get enough volume through the plugged strainer, and pressure drops even more, to the point the engine won't run.

While chasing this problem on my '88 Grand Caravan the second time, it only acted up on really hot days, and only when dragging a tandem-axle enclosed trailer that's bigger and heavier than the van. I could see the fuel pressure gradually drop from 50 psi to as low as 15 psi, which is when the engine would start to sputter and surge. It ran fine yet as low as 20 psi. That surprised me because GM engines are well-known to not run well and often not even start if fuel pressure is just five pounds too low.

By lifting the accelerator pedal for a fraction of a second, fuel pressure would pop right back up to 50 psi, then it took about 20 seconds to drop to 20 psi. By watching the gauge, I was able to nurse it home 50 miles with that trailer. A second new strainer solved that problem.

This same problem occurred with two older carbureted engines, but since those didn't use a pressure regulator or return line, the symptoms was different. They just acted like they were running out of gas, so they ran better at real low speeds.

Happy to hear you solved it. Please come back to see us again.