Hisun Side-By-Side: Fuel Pressure Optimization Guide

Hisun Motors Corporation is a Chinese supplier of powersport vehicles, including ATVs and UTVs. The company has been in operation since 1988 and has established itself as a top player in the powersports vehicle market, particularly in Canada and the United States. Hisun side-by-side vehicles are known for their affordability and high quality, offering a range of features such as powerful engines, CVT transmissions, and independent suspension systems. While Hisun vehicles generally receive positive reviews for their performance and value, some common issues have been reported, including fuel pump problems such as low pressure or pump failure. These issues can affect engine performance and may require immediate repair. To maintain optimal vehicle performance, prompt maintenance and repairs are essential for addressing fuel pump issues.

Fuel pump problems

Low Fuel Pressure or Pump Failure

Low fuel pressure or a failing fuel pump can affect engine performance and may require immediate repair. This issue can be caused by a clogged fuel filter, a faulty fuel pump relay, or a bad fuel pump. To address this, check and replace the clogged fuel filter, test and replace the fuel pump relay if necessary, or replace the faulty fuel pump.

Engine Hesitation

Engine hesitation can be caused by a weak or failing fuel pump, dirty fuel injectors, or a clogged fuel system. To rectify this issue, test the fuel pump's performance, clean or replace clogged fuel injectors, and perform a fuel system cleaning.

Loud Fuel Pump Noise

A loud fuel pump may indicate a worn-out fuel pump, damaged fuel pump bearings, or loose mounting. Inspect the fuel pump for signs of wear and replace it if necessary. Ensure proper mounting and connections to reduce noise.

Insufficient Fuel Supply

An insufficient fuel supply can be caused by a failing fuel pump, a faulty fuel pressure regulator, or clogged fuel injectors. Test the fuel pump's pressure and replace it if needed. Check the fuel pressure regulator and clean or replace clogged fuel injectors.

Starting Issues

If your Hisun vehicle is having trouble starting, it could be due to a faulty fuel pump. A worn-out or dysfunctional fuel pump may struggle to supply adequate fuel during engine startup, resulting in prolonged cranking or repeated failed attempts to start the engine.

Loss of Fuel Efficiency

A faulty fuel pump can cause a reduction in fuel efficiency, leading to more frequent trips to the gas station. If you notice a decrease in the number of miles per gallon, it could be an indication of a fuel pump issue.

Engine Stalling

Engine stalling can be caused by a malfunctioning fuel pump, which disrupts the flow of fuel to the engine. This can result in abrupt stalls while driving, leaving you stranded.

Power Loss

If you experience power loss when driving up steep inclines or carrying heavy cargo, it could be due to a faulty fuel pump. The engine requires more fuel to operate under stress, and a malfunctioning pump may not be able to deliver the necessary fuel supply.

Engine Misfires

Engine misfires can occur when there is incomplete combustion in the engine cylinders due to insufficient fuel. This can be caused by a faulty fuel pump that is unable to deliver the required amount of fuel to the engine.

Whining Noise from the Fuel Tank

A whining noise coming from the fuel tank region could indicate a failing fuel pump. This noise is typically more audible when the vehicle is loaded or accelerating.

Troubleshooting and Maintenance

To diagnose and address fuel pump issues, it is recommended to seek professional assistance from a certified technician or a Hisun service center. They have the expertise and equipment to accurately identify and resolve fuel pump problems. Additionally, regular maintenance and the use of high-quality fuel can help prevent fuel pump issues and ensure the longevity of the fuel pump in your Hisun vehicle.

Fuel delivery issues

Low Fuel Pressure or Pump Failure

Low fuel pressure or pump failure can affect engine performance and require immediate attention. This issue can be caused by a clogged fuel filter, a faulty fuel pump relay, or a bad fuel pump. To resolve this, check and replace the clogged fuel filter, test and replace the fuel pump relay if necessary, or replace the faulty fuel pump.

Insufficient Fuel Pressure

Insufficient fuel pressure can be caused by a failing fuel pump, damaged fuel lines, or a faulty fuel pressure regulator. To address this issue, check the fuel pump's pressure with a gauge, inspect and repair or replace damaged fuel lines, and test the fuel pressure regulator for proper functioning.

Engine Hesitation

Engine hesitation can be caused by a weak or failing fuel pump, dirty fuel injectors, or a clogged fuel system. To rectify this issue, test the fuel pump's performance, clean or replace clogged fuel injectors, and perform a fuel system cleaning.

Loud Fuel Pump Noise

A loud fuel pump noise can be indicative of a worn-out fuel pump, damaged fuel pump bearings, or loose mounting. To address this issue, inspect the fuel pump for signs of wear and replace it if necessary. Ensure proper mounting and connections to reduce noise.

Insufficient Fuel Supply

Insufficient fuel supply can be caused by a failing fuel pump, a faulty fuel pressure regulator, or clogged fuel injectors. To address this issue, test the fuel pump's pressure and replace it if needed, check the fuel pressure regulator, and clean or replace clogged fuel injectors.

Fuel Injector Issues

Fuel injector issues can be caused by dirt in the fuel injector, wear and tear, or contaminated or poor-quality fuel. These problems can lead to rough idling, engine stalling, engine misfiring, decreased engine power, and low fuel economy. To resolve these issues, examine the fuel for contaminants and replace it if it has been sitting in the tank for several months. If the fuel is not the issue, clean any debris from the fuel injector using a recommended fuel injector cleaner and replace it if necessary. Regular fuel system cleaning can help reduce the chances of fuel injector problems.

Fuel Quality and Level

The quality and level of fuel in the UTV can also impact its performance. Always use high-quality fuel from reliable suppliers to reduce the chance of pollutants entering the fuel system and potentially damaging the fuel pump. Additionally, ensure that the fuel tank is filled before starting the UTV, as a low fuel level can lead to fuel pump overheating and premature failure.

Maintenance Tips

To prevent fuel pump issues and ensure optimal performance, proactive maintenance is key. Here are some tips:

• Regularly replace the fuel filter to protect the fuel pump from impurities.
• Maintain at least a quarter tank of fuel to keep the fuel pump submerged and cool.
• Use environmentally friendly, clean, high-quality fuel to prevent pump damage.
• Periodically check for leaks, damage, and worn-out parts.
• Clean the fuel tank periodically to avoid clogging.
• Seek expert assistance from a certified technician or authorized service center for fuel pump repairs or replacements.

Fuel gauge and tank

The fuel gauge and tank of a vehicle are essential components that work together to indicate the amount of fuel available. In this case, the focus is on the Hisun UTV SxS, with specific years mentioned being 2013, 2015, and 2021.

The fuel gauge consists of two main parts: the sending unit, which is located inside the fuel tank, and the indicator unit, usually mounted on the dashboard. The sending unit typically uses a float connected to a potentiometer. As the fuel level decreases, the float drops, causing a change in resistance, which is measured by the indicator unit. This unit then displays the amount of fuel in the tank, often using "F" for full and "E" for empty, or "1" and "0" respectively.

Some fuel systems also include a "low fuel" light, which illuminates when the resistance reaches a certain point. Additionally, since the early 1990s, many fuel gauges have incorporated an icon and arrow indicating the side of the vehicle where the fuel filler is located. This addition was first introduced by Ford Motor Company designer Jim Moylan.

It is important to note that the electrical system of the fuel gauge can pose a safety risk due to the potential for fire and explosion. This risk has led to the development of alternative methods, such as magnetoresistance type fuel level sensors, which are commonly used in small aircraft applications and provide increased accuracy and safety.

Now, let's shift our focus to the specific issues and discussions surrounding the Hisun UTV SxS fuel gauge and tank. Several users have encountered problems with their vehicles not starting or experiencing a lack of spark and fuel. For instance, a user with a 2021 Hisun Forge 250 mentions that when they turn the key, the relays don't click, and the fuel pump doesn't activate. However, they found that hot-wiring the pump made it functional, leading them to suspect a wiring issue.

Another user with a 2013 Hisun 500 UTV shares a similar issue, where their vehicle cut out while parked and now won't start. They have replaced several parts, including the fuel pump, ignition coil, and spark plug, but the problem persists.

In addition to these specific cases, there are also discussions about fuel gauge accuracy and potential leaks. One user with a 2015 Hisun HS500 inquires about the accuracy of the fuel gauge, while another user with a 2010 Hisun 500 mentions a recurring issue where their vehicle won't start unless they pour gas directly into the plug hole.

While the provided sources don't offer direct solutions to all the issues mentioned, they highlight the range of challenges owners of the Hisun UTV SxS may encounter with their fuel gauge and tank. It is always recommended to consult a qualified technician or mechanic for proper diagnosis and repair to ensure the safety and optimal performance of the vehicle.

Fuel pump maintenance

Weekly Visual Inspections:

Conduct routine visual checks of your fuel pump at least once a week. Inspect for leaks on the pump, filters, hoses, nozzles, joints, and fittings. Identifying issues early can prevent bigger problems and costly repairs. Keep the pump clean to preserve its functionality and prevent the spread of germs, using a degreaser and gentle cleanser. Avoid harsh solutions as they can damage the pump's components.

Spillage Management:

Fuel spills are inevitable, so it's important to clean them up promptly. Use spillage absorbent granules to soak up excess fuel, and then remove stubborn stains with a pressure washer.

Underground Tank Checks:

Regularly inspect the overfill alarms installed in your underground fuel tanks to ensure they are functioning correctly. These alarms are essential for identifying leaks and avoiding potential hazards and costly repairs.

Proactive Problem-Solving:

Stay ahead of potential issues by scheduling maintenance based on the frequency of use. Conduct weekly operational checks and monthly inspections to address any problems promptly and ensure the smooth operation of your vehicle.

Fuel Filter Maintenance:

The fuel filter plays a crucial role in shielding the fuel pump from impurities. Replace the fuel filter at the recommended intervals to maintain optimal fuel flow. Refer to the manufacturer's instructions for the suggested replacement schedule.

Fuel Level Management:

Maintain at least a quarter tank of fuel to keep the fuel pump submerged and cool. Running the vehicle with a consistently low fuel level can lead to pump overheating and premature failure.

Preventative Measures:

Use high-quality fuel from reliable suppliers to reduce the risk of pollutants entering the fuel system and damaging the pump. Additionally, consider using fuel additives to maintain and clean the fuel pump.

Diagnosis and Repair:

If your Hisun vehicle exhibits symptoms such as engine sputtering, trouble starting, reduced fuel efficiency, or engine stalling, seek expert diagnosis and repair. A skilled technician or authorized service center can test fuel pressure, inspect fuel lines and connections, and utilize diagnostic tools to identify and rectify the issue.

Compatibility and Upgrades:

When upgrading your fuel pump, ensure compatibility with your specific Hisun model and engine configuration. Check fuel system specifications, electrical compatibility, and consult reliable manufacturers or mechanics for advice.

Seek Expert Assistance:

Fuel pump repair or replacement requires technical expertise and specialized equipment. Consult a certified technician or authorized Hisun service center for accurate diagnosis, proper repair, or replacement, ensuring optimal performance of your vehicle's fuel delivery system.

Fuel pump replacement

Overview

The fuel pump is a critical component of a vehicle's fuel system, responsible for delivering fuel from the tank to the engine. Over time, fuel pump internal components can degrade or become damaged, leading to reduced performance or failure. A faulty fuel pump can cause various issues, such as engine misfires, difficulty starting, and reduced fuel efficiency. Therefore, it is essential to promptly diagnose and address fuel pump problems to ensure optimal vehicle performance and avoid breakdowns.

Common Fuel Pump Issues

Before replacing the fuel pump, it is essential to identify and understand common fuel pump issues in Hisun vehicles:

• Fuel delivery problems: Low pressure or complete pump failure can affect engine performance and require immediate repair.
• Engine hesitation: A weak or failing fuel pump, dirty fuel injectors, or a clogged fuel system can cause the engine to hesitate or stumble during acceleration or at high speeds.
• Loud fuel pump noise: This can be due to a worn-out fuel pump, damaged fuel pump bearings, or loose mounting.
• Insufficient fuel supply: A failing fuel pump, faulty fuel pressure regulator, or clogged fuel injectors can lead to an insufficient fuel supply to the engine.
• Engine misfires and stalling: Incomplete combustion in the engine cylinders due to insufficient fuel can cause engine misfires and sudden stalling.
• Trouble starting: A faulty fuel pump may cause difficulty in starting the engine, requiring multiple attempts or prolonged cranking.
• Loss of fuel efficiency: A faulty fuel pump can reduce fuel efficiency, resulting in reduced miles per gallon.

Diagnosis and Repair

To diagnose fuel pump issues, a systematic approach is necessary:

• Visual inspection: Inspect the fuel pump and its components for any signs of deterioration, leaks, or faulty connections. Check for fuel stains or odours near the fuel tank and fuel lines.
• Fuel pressure test: One of the most reliable methods is to measure the fuel pressure delivered by the fuel pump to the engine. Abnormally low or inconsistent pressure readings could indicate a fuel pump issue.
• Fuel volume test: This test evaluates the fuel pump's ability to deliver an adequate volume of fuel to the engine over a set period.

Replacement Options

When a Hisun fuel pump is faulty or has failed, several replacement options are available:

• Repair or replacement of individual components: In some cases, individual fuel pump parts, such as the fuel pump motor or electrical connections, can be repaired or replaced instead of replacing the entire assembly.
• Full fuel pump replacement: If the fuel pump is severely worn or damaged, or if repair is impractical or uneconomical, a full fuel pump replacement may be necessary. Ensure that the replacement pump is compatible with your specific Hisun model and engine configuration.

Maintenance Tips

To avoid fuel pump issues and ensure its longevity, proactive maintenance is essential:

• Use high-quality fuel: Sourcing fuel from reliable suppliers reduces the risk of impurities entering the fuel system and damaging the fuel pump.
• Regular fuel filter replacement: The fuel filter shields the fuel pump from impurities. Replace it at the recommended intervals to maintain fuel flow and prevent clogging.
• Maintain fuel tank level: Keeping the fuel tank at least a quarter full helps keep the fuel pump submerged and cool, reducing the chances of overheating and premature failure.
• Periodic inspections: Regularly check for leaks, damage, and worn-out parts.
• Use environmentally friendly fuel: Clean, high-quality fuel can help prevent pump damage.
• Consider fuel pump additives: In some cases, additives can help maintain and clean the fuel pump.

Upgrading the Fuel Pump

Upgrading the fuel pump can offer several performance advantages:

• Improved fuel flow and pressure regulation: A performance fuel pump typically has a higher flow rate, ensuring better fuel delivery and pressure regulation, even under demanding conditions.
• Increased fuel capacity: A higher-capacity fuel pump can deliver a larger volume of fuel to satisfy the demands of modified engines or increased power output.
• Enhanced engine performance: Upgrading the fuel pump can improve acceleration, throttle response, and overall engine performance.

When upgrading the fuel pump, ensure compatibility with your specific Hisun model and consider upgrading the fuel lines to accommodate greater fuel flow.

Frequently asked questions