Ok I started noticing it about a year ago sometimes it would turn over a few seconds before it started. It didn’t happen very often then. About a month ago it started getting more frequent. Now it does it every time I try to start it, it turns over for about 5 seconds before it starts. I haven’t checked anything yet but first thing that comes to my mind is a fuel pump. Is there any troubleshooting techniques I could do to rule anything out before I spend 200$ on a fuel pump? It is a 2001 3.9L with 120k miles. Thanks

 

test the fuel pressure first.

 

The fuel pressure regulator is an internal part of the fuel pump. The fuel pressure regulator has a check valve in it that has failed, and when the truck is parked overnight or for any other considerable length of time, the bad check valve lets all the fuel bleed back out of the fuel line. That's why you have to crank the engine over for a longer period of time before it finally starts - the fuel pump has to re-prime the fuel back into the fuel line and injectors. This is a common problem on Dakota fuel pumps and it usually happens around 120,000 miles. It happened on my truck around 122,000 miles.

You can buy a cheap fuel pressure/fuel pump tester gauge at Harbor Freight Tools:

http://www.harborfreight.com/fuel-pu...ter-93547.html

You can start by relieving the fuel rail pressure. Remove the gas cap, remove the fuel pump relay from the Power Distribution Center and start the truck. Let it run a little while, it will start to run rough and then shut off. Briefly crank the engine over a couple more times to get any residual fuel out of the lines, then reinstall the fuel pump relay and gas cap.

Connect the tester gauge to the test port on the driver's side fuel rail and start the engine. It will take a few extra seconds to start because there is no fuel in the line at first. While the engine is idling you should have between 47 and 52 psi on the tester gauge. Any less pressure indicates a weak or failing fuel pump. When you turn the engine off, leave the gauge connected to the fuel test port. If the pressure drops below 30 psi within 5 minutes of shutting down the engine, the fuel pressure regulator check valve is bad. On my truck the gauge hit 20 psi and was still falling in less than 3 minutes.

I replaced my fuel pump myself. It was not too hard of a job. Be sure to disconnect the battery before you start replacing the fuel pump. You don't want even the slightest chance of a spark when working with or around gasoline. Try to run the tank down as close to empty as you can, so it will not be so heavy when you remove the tank to replace the fuel pump. Some guys here have removed the bed for access to the pump, that works too if you have a few friends available to move the bed off and back on to the truck. I have read that on Quad Cabs the fuel tank and fuel pump sits further back under the cab so it is not possible to get to the fuel pump by removing the bed. The tank has an alignment mark on it and the new fuel pump will have an alignment mark on it too. Make sure to position the new pump in the tank with the two marks lined up facing each other. This puts the fuel pump in the correct position inside the tank to allow enough room for complete free travel of the fuel level sending unit arm. If the tank is not positioned correctly the arm will rub on the inside wall of the tank and give incorrect level readings on the fuel gauge in the dash.

I bought my fuel pump at Advance, its their Airtex brand pump and the regular price was $240.00. I used one of their online discount codes, paid online and only paid $180.00 for my new fuel pump. If you choose to buy from Advance, you can do a Google search for "Advance Auto Parts discount codes" and the list should come up. Rockauto.com might have a good price on a new fuel pump too if you have the time to wait for shipping.

Jimmy

 

The post from Jimmy was right on. Our truck is a 2001 quad cab, 4.7, 2x2.
Let me add my experience from today:
- Used a fuel pressure gauge to test for the problem. The test port is a Schrader valve in the middle of the passenger side fuel rail on between 4 and 6 plug coils. My bad unit measured 45 PSI running and 0 immediately at shutoff. Not good.

Although not related to the fuel pump, I found and replaced 3 cracked leaky vacuum lines on the drivers side and routed under the fuse box and connected to a 2 port valve, which are part of the gas fume evap system I believe. I could actually hear the vacuum leak very distinctly. Replacing these helped, but did not completely fix the hard starting issue.
So I purchased a new NAPA fuel pump for $215 and went to work.

- Waited until my tank was almost empty.
- Got a friend to help. Highly advisable!
- Jacked the entire rear end and braced with jack stands.
- Removed the drivers side rear tire.
- Removed the mud guard in front of the tire to access the filler/overflow hoses.
- Removed the filler and overflow hose clamps and hoses.
- Removed a fume evap hose from the front of the fuel tank.
- Removed the 2 nuts from the 2 tank straps; you'll need a long (12")extension for this.
- Pulled the straps down and bent them slightly towords the drivers side.
- Pulled the tank towards the rear; the front of it rests on a non-removable crossmember.
- As the tank is pulled back it will begin to want to drop down from rear, but it's got to clear the rear end, so it's pulling back and letting it drop at the same time. But wait! You can't drop the tank completely yet.
- Now the 2 tricky parts: The fuel line and the electrical connector.
- The fuel line is not long enough to let the tank drop to the floor. So you have to reach in and remove it while the tank is only partially lowered in the back and the front is still high up on the crossmember. The fuel hose has a blue retaining clip with 2 small tabs 180 deg opposite sides of the hose that must be squeezed together before the hose will slide off. Be careful, the clip can fall off the hose and be lost, and the hose will not lock in place again without it.
- The electrical connector is mounted on the frame with two one-way tabs; pry it off with a screwdriver; the new pump had tabs on it's connector.
- The connector has a red tab that must be slid off to one side. Probably not really needed.
- The truck side of the connector has a release tab that must be squeezed, with fingers or pliers, before it will come apart. This is why I feel the red tab is redundant.
- Now the tank can be completely removed by continuing to slide it back and down.
- Observed the old fuel pump and noticed the arrow on the pump which is pointing towards a set of double lines molded into the tank; the new pump must be oriented this way in order for the float to work properly.
- Cleaned the area around the fuel pump with compressed air of lots of dirt and debris that could contaminate the tank.
- Together my friend and I unscrewed the large plastic securing ring by hand. You can use a strap wrench to remove it; my oil filter strap wrench did not quite have enough length to encircle the ring, but if yours does it would be easier than by hand.
- Pulled the old pump out; found the pickup filter had fallen off and was just laying in the bottom of the tank; fished it out and found it dirty, but who knows how long it's been non-operational.
- Re-installed everything basically in reverse order.
- Re-tested the fuel pressure; 50 PSI running, 45 PSI shut down. Starts awesome! Yeah!

 

I havnt got around to fixing it yet. i have noticed that my mileage has went way down sense the hard starts. Would the fuel reg or pump cause mileage loss?

 

I have the same problem - 10mpg I am not convinced of the fuel pump being my issue thogh as mine was replaced shortly before I bought the truck a year ago, and I still have the hard start issue. You can use the pressure guage to narrow down the location of your leak down by compressing the fuel line just after the guage. If the pressure still drops, your pressure loss is between the fuel pressure guage and your injectors if it stays up, then your pressure loss is somewhere from the pump to the area that you closed off.
I believe I stated that correctly...

 

I spliced the section on fuel from the manual it may help you get some answers http://www.rp95.com/fuel.pdf

Loads of info