1998 dodge

I have a 1988 Dodge pickup 1500 with a 5,9 gas engine. It used to pop right over all the time. Now, in the morning, I have to crank it forever until it starts, and if it sits for 1 hour or more, same thing (have to crank for a long time). It is my understanding there is a valve called a one day valve that holds pressure on the gas line. Is it possible this valve is not working properly? And if so, do I have to replace fuel pump to fix problem? once started it starts up with no problem until it sits for hour or more then hard to start.

I’ve never heard of a “one day valve”, but fuel injection systems are designed to maintain pressure. When it does start, does a cloud of smoke pour out the exhaust? Has your gas mileage dropped? Here’s two things to try: (do these on separate occurrences of the problem, as they will help in troubleshooting) The next time it won’t start easily, try starting it with the gas pedal held to the floor. Then the time after that when it won’t start, try turning the key on, but not starting it. Wait a few seconds, then turn the key off and back on again. Repeat this 3 or 4 times, then start the vehicle normally, with your foot off the gas. (this will re pressurize the injection system) Then on the next occurrence, try a combination of both.

If the vehicle started easier when you held the gas pedal to the floor, I would suspect you possibly have a leaking fuel injector that is flooding the engine. If it started easier by doing the trick with the key, you may have a weak fuel pump, or you could still have a leaky injector, or both. If it starts easier when doing a combination of both tricks, you could still have a leaky injector, or you may have other problems with the fuel injection system, such as a bad pressure regulator. With a 25 year-old vehicle, all things that suck are possible!

Are you sure it is called a “one-day” or a “one-way”?

When was the last time the spark plug, plug wires, rotor and distributor cap (if applicable) were replaced? I would start.

I’m sure that what someone meant was probably the check valve in the fuel pump. The fuel lines will lose pressure over time, but they should stay full of fuel. Its the job of the check valve to keep the lines full - and a check valve is a “one-way” valve. It only lets things though in one direction - unless its broken.

Try the thing oblivion said - turn the key to run & wait a few seconds for the fuel pump; then back off; then back to run; back off…I’d go at least 5-6 times. If that gets it to start right up every time then it probably is the check valve which is built into the fuel pump. So, yes, you would have to replace the fuel pump to fix it.

I don’t understand why the "on, off, on , off, 5 or 6 times, why not turn it on and wait for the fuel pump to fill up the lines, then start the engine??

The pump does not run long enough to pressurize the system in one try if it’s weak…When you turn on the key, it only runs for less than a second then it stops and will not run again until the engine starts…

Balony!! If you can prove that, I will take back my Balony!

You can prove it to yourself. Turn the key to the run position and listen. You’ll hear it hum for anything from 1-3 seconds and then it stops. That’s what it does. If you can’t hear it from inside the car, pull the gas cap & have an assistant work the key while you stick your ear next to the filler neck.

If you’re pump does continue to run then something is malfunctioning.

It stops running when it has pressurized the system.

EllyEllis, go read the factory service manual and it will explain how the computer energizes the fuel pump for a few seconds and then shuts it down until the car is started then fires it up again. Waiting about 20 seconds between key turns, resets the computer and will energize the pump again.

Besides the check ball, you could also have an injector that is sticking open and thus draining the fuel pressure. A fuel pressure tester would show you are losing pressure but you would need to clamp off the return line to isolate it to the injectors or check valve.

There is nothing measuring the pressure as I understand it, so the pump cannot keep running until the system is pressurized. So the best guess is to run it for a few seconds. (correct me if I’m wrong)

Correct. It doesn’t know what the pressure is. The computer just times it to run for a couple seconds or until the engine starts, then turns the pump on again. If it doesn’t see the crank signal, the pump is de-energized again and won’t repeat the cycle again for maybe 20 seconds.

thank you one and all, yes it is a one way valve once I put my glasses on to read book. turning key on for extended time does not work, however, turning key on about 4 times does work (starts right up ) walla- a weak fuel pump or a bad check valve it is time for action.

Well, EllyEllis, you’ve been proven wrong. When are you going to take it back?

Well, I guess I will do that now. (can I have mustard with that?) It sounds crazy to me, but it must be so. However I think I’ll check out my van and see if it works that way.