Replacing Fuel Regulator In Your 03 Fatboy: Step-By-Step Guide

If you're looking to replace the fuel regulator on your 2003 Harley Fatboy, you've come to the right place. This process can be a bit tricky, but with the right tools and guidance, you'll be back on the road in no time. First, let's talk about the symptoms of a faulty fuel regulator. You may notice that your bike starts up fine, but after warming up, it idles down and eventually dies. This could be due to a hole in the fuel line inside the fuel tank, which is a common issue. To verify this, you can use a fuel pressure gauge to test the pressure.

Now, let's get into the replacement process. Start by disconnecting the negative feed from the batteries. Remove the belt from the pulleys and the air intake. You'll need to loosen a few hose clamps and remove the air assembly. Next, disconnect the connectors on the AC unit and remove the unit by taking out the mounting bolts. You'll also need to remove the coolant stack and the metal piping. Loosen the hose clamp on the coolant pipe and remove the hose.

At this point, you can access the fuel regulator. Be sure to spray some penetrating oil on the bolts before removing them, as they can be difficult to take out. Install the new fuel regulator, making any necessary adjustments to the fuel line or connector. Finally, reassemble everything by following the steps in reverse.

It's important to note that this process may vary slightly depending on your specific model and setup. Always refer to your owner's manual or seek the advice of a qualified mechanic if you're unsure about any steps.

How to identify a faulty fuel regulator

A faulty fuel pressure regulator can cause severe damage to your vehicle, so it's important to identify the issue early on. Here are some tell-tale signs that your fuel pressure regulator is failing:

• Fuel leaks: If you notice fuel leaks, especially after parking your vehicle for a while, it could indicate a faulty regulator. Check for fuel droplets under your vehicle or cracks in the regulator itself.
• Fuel odour: If you smell fuel when checking the oil level with the dipstick, it suggests an issue with fuel pressure.
• Black smoke from the exhaust: Incomplete combustion due to a faulty regulator will result in black smoke from the exhaust.
• Engine performance issues: A faulty regulator may cause engine misfires, low acceleration power, rough idling, stalling, and poor fuel economy.
• Check engine light: Illuminated check engine light could be triggered by various issues, including a faulty regulator, so further diagnostics are needed.
• Engine won't start: Insufficient fuel pressure due to a faulty regulator can prevent the engine from starting.
• Excessive fuel pump noise: Unusual or excessive noise from the fuel pump may indicate an issue with fuel pressure.
• Fuel dripping from the tailpipe: Finding fuel on the tailpipe is unusual and could be a sign of a faulty regulator.
• Vacuum hose issues: If you find gasoline in the vacuum hose, it confirms an issue with the fuel pressure regulator.
• Loss in acceleration: A faulty regulator can affect the amount of fuel supplied to the engine, resulting in reduced acceleration.

If you suspect a faulty fuel pressure regulator in your 2003 Harley-Davidson Fatboy, it is best to consult a professional mechanic for diagnosis and repair. They will have the expertise and equipment to test the fuel pressure regulator and recommend the necessary repairs or replacements.

Step-by-step guide to replacing the fuel regulator

Preparation

• Disconnect the negative feed from the batteries.
• Using a 1/2" breaker bar, remove the belt from the pulleys by placing the head of the bar into the square socket on the belt tensioner. Push it towards the passenger side and lift it off the AC compressor unit.
• Remove the air intake by loosening the three hose clamps. Pull off the "6.6 Turbo Diesel" cover and then the second clamp. The third clamp is by the air filter.
• To remove the assembly, simply twist and pull from the engine side.

AC Unit

• Disconnect the two connectors on the AC unit. They are marked with blue circles.
• Using a 15mm socket, remove the four bolts that mount the unit to the engine. These are marked with white circles and arrows.
• Move the AC unit out of the way by flipping it towards the passenger side battery.

Coolant Stack

• Open the clip (marked with a white circle) that holds the wire harness with a sharp object.
• Remove the red bolt from the thermostat housing and set the bracket aside.
• Remove the two bolts (green circles) that hold the metal piping to the engine.
• Using a 13mm socket, remove the four bolts marked with blue circles. The bolt at the front does not need to be removed.
• Loosen the hose clamp (white circle) on the coolant pipe.
• Take a straight pick and insert it into the hose end (blue circle). Move it around the circumference of the pipe to break the connection.
• Pull the hose off the pipe and wedge it against the brake cylinder and the fuse box.
• Lift the pipe off the engine and flip it towards the turbo.

Turbo Horn Removal

• Disconnect the sensor on the manifold.
• Using a swivel socket and/or a 10mm wrench, remove the three bolts on the inlet horn.
• To remove the left bolt, take a long pick or screwdriver and put inward pressure on the bolt.
• Once all three bolts are removed, pull out the horn.

Fuel Line Removal

• Disconnect the FPR connector (white circle).
• Using pliers, remove the two fuel line clamps (blue).

FPR Removal

• Spray some penetrating oil on the bolts.
• Try to clean the heads so that your bit will seat completely or you will strip them out.
• Remove the three bolts (white circle) from the FPR/CP3.

Installing FPR

• Use a dab of weatherstrip and gasket sealer on the bolt so you can place it in the lower hole.
• Once the thread is started, pull the bit out of the bolt and it will be free.
• Once the sealer dries, pick it out or leave it in so you can pull the "plug" out if needed in the future.
• If the connector won't go in, loosen the banjo bolt and bend the pipe so it can be plugged in.

Reassembly

Put everything back together by reversing the steps above.

Tuning

• This step is untested but acquired from Dieselplace.com. It is only necessary if you installed a non-LB7 FPR.
• The following step is for those with EFIlive access.
• See the attached table for tuning advice.

Common issues when replacing the fuel regulator

When replacing the fuel regulator on a 2003 Harley-Davidson Fatboy, there are a few common issues that you may encounter. Here are some detailed paragraphs describing these issues:

One issue that has been reported by Fatboy owners is a problem with the fuel line. The stock fuel hose is made of plastic and can rub on the inside of the tank, eventually leading to a hole that causes a lack of fuel pressure. This can result in the bike starting when cold but dying once the engine warms up. To verify this issue without disassembling the fuel system, a fuel pressure gauge can be used to test the pressure.

Another issue that has been encountered is related to the O-rings on the fittings at the fuel pump and regulator. It is important to ensure that the O-rings are properly seated and that the fittings are securely connected. Failure to do so can result in fuel leaks and affect the bike's performance.

Additionally, there have been reports of the fuel pressure regulator housing cracking, which can cause the regulator to come out of its housing. This issue was reportedly common enough that Harley-Davidson issued a recall for it around 2006.

Furthermore, issues with the fuel pump itself can also occur. In some cases, the pump may not produce enough initial pressure to cause the pressure regulator to close, resulting in low fuel pressure. A faulty fuel pump can also cause fuel to spray out from the back of the regulator.

Lastly, there have been reports of issues with the corrugated hose coming out of the tank, which can develop pinhole leaks on the ridges that sit on the tank bottom. This can lead to fuel leaks and affect the fuel pressure.

Tools required for replacement

To replace the fuel regulator on a 2003 Harley-Davidson Fatboy, you will need the following tools:

• A new fuel pump with a seal, regulator, and fuel filter (specific to your bike model)
• Basic tools for mechanical work (e.g., wrenches, screwdrivers, etc.)
• A fuel pressure gauge (to test the system)
• A new fuel line, if the old one is damaged
• O-rings for fittings at the pump and/or regulator

It is important to ensure that you have the correct replacement parts for your specific bike model and year before starting the replacement process. Additionally, having a basic understanding of motorcycle mechanics or seeking the assistance of a professional mechanic can be beneficial for a successful and safe replacement.

Safety precautions when replacing the fuel regulator

When replacing the fuel regulator on your 2003 Fatboy, there are several safety precautions you should take to ensure a successful repair job and avoid any accidents. Here are some detailed instructions to guide you through the process safely:

Work in a Well-Ventilated Area:

Choose a work area with adequate ventilation to avoid inhaling harmful fumes from the fuel system. Keep a safe distance from appliances with open flames, such as water heaters and dryers.

Relieve Fuel System Pressure:

• Before starting any work on the fuel system, it is crucial to relieve the system pressure. For Throttle Body Injection (TBI) models, you can simply turn off the engine, as the pressure drops a few seconds after shutdown.
• For TBI models and multiport fuel injection systems, you can remove the fuel pump fuse or relay, start the engine, and let it idle until it stalls.
• For Electronic Fuel Injection (EFI) systems, locate the Schrader valve on the fuel rail. Cover the valve with a rag and carefully depress it with a screwdriver to release the pressure. Don't forget to loosen the fuel filler cap afterward.

Disconnect the Battery:

Disconnect the negative (black) battery cable to prevent any accidental electrical issues during the replacement process.

Wear Protective Gear:

Always wear safety gloves and goggles to protect your eyes and hands from fuel exposure. It is also recommended to wear long sleeves and pants to avoid any skin contact with fuel or chemicals.

Handle Fuel Lines with Care:

When working with fuel lines, ensure that all connections are properly tightened to avoid fuel leaks. Pay close attention to the fuel return line and the supply hose during the replacement process.

Clean the Regulator Mounting Base:

Before installing the new regulator, thoroughly clean the gasket mating surface on the regulator mounting base. This ensures a proper seal and prevents leaks.

Lubricate O-Rings:

When installing the new regulator, lightly coat the O-ring with clean engine oil. This helps create a tight seal and prevents damage to the O-ring.

Test for Leaks:

Once you've installed the new regulator, reconnect the battery and turn the ignition key to the "On" position. Check for any fuel leaks around the new pressure regulator and the fuel lines.

Reset Settings:

If you did not use a battery saver during the replacement process, you will need to reset all the settings in your vehicle, such as your radio, electric seats, and electric mirrors.

Test Drive:

After the replacement, take the bike for a test drive to ensure that the new fuel regulator is functioning correctly. Listen for any unusual engine sounds or vibrations and monitor the dashboard for any warning lights.

Frequently asked questions