How to: Fuel pump replacement - 2000 Explorer Sport

[2000StreetRod]

Background

In 1999 Ford switched from a return fuel system with a rail mounted fuel pressure regulator (FPR) to a returnless fuel system with a rail mounted fuel pressure damper and a tank installed FPR. The fuel pressure for the returnless system should be 60 to 65 psi for just about any condition when the ignition switch is in Run. My stock fuel pump was still functional but I needed to install a high flow pump in preparation for adding an M90 supercharger and high flow fuel injectors. In searching the forum I found threads for replacing the fuel pump without removing the fuel tank by cutting a carefully measured access hole in the body panel above the pump. I also found threads about removing the fuel tank and a couple threads about replacing the return fuel system pump. I decided to generate this thread describing removal of the fuel tank, removal of the fuel pump assembly, replacement of the pump, hose and "sock", installation of the pump assembly and installation of the tank on a returnless fuel system.

Note: The Aeromotive Stealth 340 fuel pump I chose to install is not designed for returnless fuel systems and draws about 16 amps at 65 psi. It's 340 liter per hour capacity greatly exceeds the needs of my future M90 equipped engine. According to the manufacturer it can support up to 700 flywheel horsepower on a forced induction fuel injected engine with high flow fuel filter and AN-06 or equivalent fuel line. One reason I selected the pump is it highly compatible with pulse width modulated controllers which I plan to incorporate in the future. I do not recommend this pump for your Explorer nor does Aeromotive.

Fuel tank removal

1. Reduce the fuel in the tank to nearly empty. When my fuel gauge dropped to 1/8 I placed a portable fuel container with 2 gallons of fuel in the vehicle and continued driving until the "CHECK GAGE" illuminated. If your vehicle does not run, or it is not convenient to wait until the tank is nearly empty by driving, then you will have to find some way to empty the tank. If you decide to siphon fuel out of the tank I suggest using the vent port instead of the filler port. The vent port connects to a tube with a 90 degree downward bend in the tank so a hose will go to the bottom of the tank.

The larger diameter filler port connects to a tube with a 45 degree downward bend in the tank. Pushing a siphon hose thru the port results in it contacting the front side of the tank wall. If the pump still works you can pump out the fuel into a container. One way is to disconnect the inlet to the fuel filter and attach a hose to the feed pipe from the tank. While you're doing that consider replacing the fuel filter if it's been 50K miles since it was last replaced. See Why change fuel filter? Don't forget to relieve the fuel pressure prior to disconnecting the feed line to the filter.

2. Relieve the fuel pressure. There are several ways to accomplish this. You can remove the fuel pump relay in the Battery Junction Box (BJB), start the engine and let it run until there is no longer any fuel pressure. You can remove the fuel pump Fuse 9 in the BJB, start the engine and let it run until there is no longer any fuel pressure. You can activate the Inertial Fuel Shutoff, start the engine and let it run until there is no longer any fuel pressure. You can disconnect the fuel pump electrical connector C311 attached to the inner side of the left frame rail forward of the tank. This connector is not available on 2001 and later models. In my case I just let the vehicle sit overnight allowing the pressure to bleed off thru the check valve in the fuel pump assembly and then relieved what was left (none) by depressing the Schrader valve in the engine compartment.

3. Disconnect the cable from the negative terminal of the battery. I disconnected both the negative and the positive connectors so I could clean them and the battery posts.

4. Block the front wheels to prevent the vehicle from moving forward or aft.

5. Lower the spare and move it away from under the vehicle to improve access and visibility.

6. Loosen the lug nuts on the left rear wheel.

7. Jack up the rear axle and place jack stands under it.

I used 6 ton jack stands under the axle and 2 ton stands under the springs for backup.

8. Remove the left rear wheel.

9. My Sport is 2WD but 4WD models may have a fuel tank shield and skid plate to remove.

10. Loosen the vent hose clamp at the tank and disconnect the hose.

11. Loosen the fuel filler hose clamp at the tank and disconnect the hose.

I covered the ports with aluminum foil to reduce fumes in the garage and keep out dirt.

12. Remove the fuel tank ground strap if any (none on my Sport).

13. My Haynes Repair Manual says to disconnect the fuel pump electrical connector inboard of the driver side frame rail and forward of the fuel tank on 2000 and earlier models. My 2000 Explorer Workshop Manual does not mention the step and I found it was unnecessary.

14. Support the tank with jack(s). I supported the fuel tank with scissor jacks and boards for better control.

15. Completely unscrew the bolt holding the rear tank strap in position. It is located above the driveshaft so I used a U joint attached to the socket and a 12 inch extension.

16. Remove the two bolts attaching the front of the tank to the support bracket.

17. My Haynes manual says to bend the tank strap down and out of the way but I chose to remove it which agrees with my Workshop Manual. I pushed the tank sideways toward the driveshaft far enough to swing the strap rearward and align the flat head on the other end with the slot in the frame rail. Then it just dropped down and was free.

18. Contrary to the above photo, lower the rear of the tank about 1/2 inch and then lower the front of the tank while pushing the tank rearward until the tank clears the mounting bracket. There's an aggravating protrusion on the inboard section of the bracket that must be cleared. This avoids stressing any of the tank connections.

19. Lower the rear (and front) of the tank until you can access the fuel line, electrical connector and vapor hose connector thru the wheel well. Do not lower the tank so much that any hose is supporting the weight of the tank.

20. Disconnect the fuel line.

21. Disconnect the vapor hose connector.

22. Disconnect the electrical connector that may be attached to inboard side of the frame rail.

 

[2000StreetRod]

Fuel pump assembly removal

1. Disconnect the electrical connector from the transducer.

2. Clean the top of the tank with a brush and blow away the dirt.

3. Mark the tank and the fuel pump assembly with alignment arrows.

4. Remove the bolts attaching the fuel pump assembly to the tank.

5. Carefully raise the fuel pump assembly out of the tank while moving it fore and aft and side to side as needed to clear the assembly components as they encounter the diameter of the opening.
Caution: The fuel level float sensor is very easy to damage if pressure is applied to the float arm. Take your time so you end up with a reliable fuel gauge reading.

The photo below shows the extracted fuel pump assembly. Inspect the large seal for cracks and drying. Inspect the fuel pressure regulator (center) to output tube hose for deterioration. Make sure the hose clamps are tight and in good condition. Make sure the corrugated return hose is in good condition.

 

[2000StreetRod]

fuel pump replacement

1. Remove the fuel pump clamp screw and detach the clamp.

2. Pull the pump away from the assembly to gain access to the electrical connector.

3. Loosen the hose clamp on the fuel pump hose at the fuel pressure regulator (FPR) and pull/pry the hose from the FPR.

4. Disconnect the pump electrical connector and remove the fuel pump.

5. Pull the pump electrical wire and connector away from the FPR and hose for easy access.

The online Stealth 340 installation instructions were identical with what came with the pump and totally inadequate so my own instructions follow. The fuel pump kit included a little bag containing fuel pump inlet port to screen adapter, a metal ring and an internal tooth lock washer. By examining the parts I determined how they should be assembled.

6. The plastic piece shown below is the adapter. Slip the metal ring shown over the pump side of the adapter.

The internal tooth lock washer is a "keeper" to prevent the adapter from separating from the pump.

7. Insert the keeper into the slot in the adapter with the concave side toward the pump as shown below. The small hole shown in the photo below/right is the vapor-purge port. Any blockage or restriction to this port may result in slow or no priming and may damage the pump due to dry run.

The keeper locks onto the tit on the center/end of the pump. Unfortunately, the pump inlet port is a loose fit to the adapter which would allow fuel to enter the pump that did not pass thru the screen when attached.

8. Apply gasket maker to the inside of the adapter opening and then install the adapter onto the pump inlet.

9. After the gasket maker has firmed, place the replacement pump in position and determine the hose length from the pump to the FPR. Cut the new hose to the required length.

10. Remove the new pump and install the cut-to-length hose on the pump and both hose clamps but do not tighten them.

11. Install the "cushion" around the pump.

12. Install the new electrical connector/wires to the new fuel pump.

13. Push the free end of the hose onto the FPR and tighten both hose clamps.

14. Position the pump in place and install the clamp and screw with thread lock. Tighten the screw.

15. Route the wires between the hose and the assembly support to the old wires and connector. Shorten the new wires (so there will be extra of the old wires in case you replace the pump again in the future) and then cut off the old connector and wires with lengths to mate (twist together) with the new wires.
Note: You may want to shorten one of the new wires more than the other to stagger the splices with the old wires.

16. Install lengths of heat shrink tubing on the wires away from the cut ends. Twist and solder the wires. Make sure to connect the fuel pump positive wire (red) to the fuel pump assembly positive wire (pink/black) and negative wire (black) to the negative wire (black). Position the heat shrink tubing over the splices and heat them to shrink.

17. Install the pickup screen ("sock") with the long end aligned with the float.

 

[2000StreetRod]

fuel pump assembly installation

1. Apply vinyl conditioner to the large seal to keep it from drying out and cracking (I used Eagle One Leather Care Cream Conditioner)

2. Carefully insert fuel pump assembly into tank while preventing the float and its arm from contacting the diameter of the tank opening.

3. Position the fuel pump assembly to align the marks made prior to removal.

4. Screw in each of the six screws until snug then torque to 80 to 107 inch-lbs in using two or more stages to avoid warping the cover plate.

5. Connect the electrical connector to the fuel pressure transducer.

 

[2000StreetRod]

Fuel tank installation

1. Position the fuel tank and support it with blocks of wood and jacks. Raise the tank.

2. Connect the fuel vapor hose.

3. Connect the fuel line.

4. Connect the fuel tank electrical supply connector near the frame rail.

5. If previously disconnected, connect the electrical connector forward of the fuel tank and inboard of the driver side frame rail.

6. If previously disconnected, connect the fuel lines to the fuel filter.

7. If the fuel tank is not empty, connect the battery, switch on the ignition and either start the engine or check the Schrader valve for pressure. My fuel pressure at engine idle is now a steady 67 psi instead of 62 psi with the stock pump. Being steady was a relief because I was concerned that the stock FPR might not have enough bypass flow capacity to keep up with the Stealth pump output. However, the increase from 62 to 67 psi represents a potential 8% richness increase at WOT (10.7:1 instead of the previous 11.6:1). My custom tune may have to be adjusted. Check for fuel leaks. Disconnect the battery.

8. Raise the rear of the tank, push the tank rearward enough to raise the front of the tank until it clears the mounting bracket. Let the tank move forward enough to rest the lip of the tank on the bracket.

9. Push the tank toward the driveshaft far enough to insert the end of the tank strap into the slot in the frame. Rotate the strap into position. Or straighten the strap just enough to insert the T shaped end into the larger T shaped opening in the frame rail. Straightening the strap any will make it more difficult to insert the strap mounting bolt in the step below.

10. Loosely install the two tank mounting bolts into the support bracket.

11. Raise the rear of the tank. Install the strap mounting bolt being careful not to cross thread the bolt. I used a jack under the strap to raise it while guiding the bolt with my other hand. Torque to 25 to 34 ft-lbs.

12. Tighten the support bracket bolts to 25 to 34 ft-lbs.

13. Remove the tank support jacks and blocks of wood.

14. Install the fuel tank filler hose and clamp. Tighten the clamp.

15. Install the fuel tank vent hose and clamp. Tighten the clamp.

16. If previously removed, install the tank skid plate.

17. Install the left rear wheel.

18. Remove the jack stands.

19. Install the spare wheel.

20. Add fuel to the tank.

21. Connect the battery.

 

[Dono]

Quick question....Did you use the smaller pick up filter screen that came with the Aeromotive pump, or did you use a larger factory style pick up screen? The reason I sak is that when I installed my first high volume pump (Not an Aeromotive) in my other 2000 Ex once the gas was below 1/4 full it was very susceptible to gas slosh and would stall accelerating, or going around corners. Id like to avoid this if possible.

 

[2000StreetRod]

Aeromotive screen

I used the screen that was provided with the pump. The fuel is always pulled from the bottom of the tank whether the tank is full or nearly empty. I didn't notice if there is a baffle in the tank around the screen area. I never let my tank get below 1/8th full. A fuel pump will overheat when pumping air. The flow of fuel cools the pump.

 

[Dono]

Okay, if you could go 1/8 tank and not stall rounding a corner you are definitely not experiencing what I'm describing. My issue starts at 1/4 tank. The weird thing is that on the highway the tank can run right down to almost nothing without an issue ( had a close call on xmas day on the highway with no gas stations open).
All I could think of that might cause the issue was the smaller tank filter
I won't worry about it though.

 

[2000StreetRod]

cornering cutout?

One forum member posted about cornering cutout only on left (I think) turns but that seemed to be an electrical rather than fuel tank issue. I can't think of an electrical reason that you'd experience the symptom when only below 1/4 tank. I've never liked exposing the electrical connections to fuel (I prefer solder and shrink wrap) but it seems to be standard practice. Anyway, fuel sloshing at the connections should not result in intermittent continuity. Nor can I think of a way that sloshing would cause the fuel pressure regulator to malfunction. It's puzzling.

 

[Dono]

Thanks Dale, I wont be concerned then. I was just wondering if you experienced this also.
When I installed the pump, I did use solder and heat shrink.
The issue does seem like the engine becomes starved for fuel, and I just assumed that the fuel 'slosh' away from the bottom of the pump assy was the culprit. It has never been a huge issue, as I have always just made sure the tank gets a fill when it hits 1/4.

On my new pump install, I'll be following this thread, as it obviously worked for you. Thank you btw.