1999 Chrysler LHS Fuel Pump: Complete Guide to Symptoms, Replacement, and Cost
If you own a 1999 Chrysler LHS and your car is struggling to start, stalling on the highway, or losing power during acceleration, the fuel pump is likely failing. The 1999 Chrysler LHS fuel pump is a critical component that delivers gasoline from the tank to the engine, and when it goes bad, your car becomes undrivable. Replacing it promptly is essential to avoid being stranded, and the job typically costs between $400 and $800 for parts and labor at a shop, or around $150 to $300 if you do it yourself with a quality replacement unit. This guide covers everything you need to know about the 1999 Chrysler LHS fuel pump, including symptoms, testing, replacement steps, and the best replacement options available.
Understanding the 1999 Chrysler LHS Fuel Pump System
The 1999 Chrysler LHS uses an electric fuel pump located inside the fuel tank. This pump is part of a module that includes the fuel level sender, fuel filter, and sometimes a pressure regulator. The pump operates at a pressure of approximately 49 to 57 psi, which is standard for the 3.5L V6 engine in this model. When you turn the key to the "on" position, the pump primes for a few seconds, then runs continuously once the engine starts. A failing pump can cause intermittent issues that worsen over time, so early detection is key.
Top 5 Symptoms of a Bad 1999 Chrysler LHS Fuel Pump
1. Engine Cranks But Won't Start
The most obvious sign is when your engine turns over but never fires up. You may hear the starter spinning, but the fuel pump is not delivering fuel to the injectors. If you have a friend listen near the rear of the car while you turn the key, you should hear a faint whirring sound from the fuel tank for 2-3 seconds. No sound means the pump is dead or the electrical connection is faulty.
2. Car Stalls or Sputters at High Speeds
A failing pump cannot maintain consistent fuel pressure, especially when the engine demands more fuel, like during highway driving or uphill climbs. The 1999 Chrysler LHS may suddenly lose power, shudder, or stall completely, only to restart after a few minutes. This is a classic sign of pump overheating or wear.
3. Loss of Power During Acceleration
If you press the gas pedal and the car hesitates or feels like it's running out of gas, even though the tank is full, the fuel pump is struggling. The 3.5L engine needs a steady flow of fuel, and a weak pump cannot keep up with sudden demand.
4. Whining Noise from the Fuel Tank
A healthy fuel pump runs quietly. If you hear a loud, high-pitched whine or humming coming from the rear of the car, especially when the tank is low on fuel, the pump bearings are likely worn out. This noise will get louder over time until the pump fails completely.
5. Engine Surges or Idles Roughly
Inconsistent fuel pressure can cause the engine to surge at idle or while cruising. The 1999 Chrysler LHS may feel like it's speeding up and slowing down on its own, or the RPMs may fluctuate at a stoplight. This is due to the pump not providing a steady volume of fuel.
How to Test the 1999 Chrysler LHS Fuel Pump Before Replacing
Before you buy a new pump, confirm it is the problem. Here are three simple tests:
Test 1: Listen for the Prime Sound
Open the driver's door and turn the key to the "on" position without starting the engine. Listen for a 2-second whirring sound from the rear of the car. If you hear nothing, the pump is not receiving power or is dead.
Test 2: Check the Fuel Pump Relay
The 1999 Chrysler LHS has a fuel pump relay in the fuse box under the hood. Swap it with a similar relay, like the horn relay, and see if the pump starts working. A bad relay is a cheap fix compared to a pump replacement.
Test 3: Test Fuel Pressure
If you have a fuel pressure gauge, connect it to the Schrader valve on the fuel rail. With the engine off, turn the key on. Pressure should jump to 49-57 psi and hold steady. If it’s low or drops quickly, the pump or regulator is bad.
Replacing the 1999 Chrysler LHS Fuel Pump: Step-by-Step
Replacing the fuel pump in a 1999 Chrysler LHS is a doable DIY job for someone with basic mechanical skills. You will need a new pump assembly, a fuel line disconnect tool, a floor jack, and safety glasses. Plan for 2 to 4 hours of work.
Step 1: Relieve Fuel System Pressure
Locate the fuel pump fuse in the fuse box and pull it out. Start the engine and let it run until it stalls. This removes pressure from the lines. Then disconnect the negative battery cable.
Step 2: Drain the Fuel Tank
The fuel tank needs to be low or empty to lower it safely. If the tank is full, use a siphon pump to drain as much fuel as possible into approved gas cans.
Step 3: Remove the Fuel Tank
Jack up the rear of the car and secure it on jack stands. Remove the exhaust heat shield, then unbolt the fuel tank straps. Disconnect the fuel lines, electrical connector, and vent hose. Lower the tank carefully with a floor jack.
Step 4: Replace the Pump Module
Clean the top of the tank, then loosen the locking ring with a hammer and punch or a spanner wrench. Lift out the old pump module. Remove the pump from the module, transfer the rubber grommet and filter sock to the new pump, and reassemble. Install the new module into the tank, tighten the locking ring, and reconnect everything.
Step 5: Reinstall the Tank and Test
Raise the tank back into place, reconnect the straps, heat shield, and lines. Add a few gallons of fuel, reconnect the battery, and turn the key to the "on" position to prime the pump. Check for leaks, then start the engine.
Why the 1999 Chrysler LHS Fuel Pump Fails Prematurely
Several factors cause early failure of the fuel pump in this model. Running the car with a low fuel tank is the most common cause. The pump relies on gasoline to cool and lubricate it, and when the tank is low, the pump overheats. Dirt and debris from cheap gas or a clogged filter can also damage the pump. Finally, the age of the vehicle means the pump's internal brushes wear out over time. Most factory pumps last 100,000 to 150,000 miles, but a 1999 LHS is now 27 years old, so failure is expected.
Cost of 1999 Chrysler LHS Fuel Pump Replacement
Here is a breakdown of what you can expect to pay:
1. DIY Replacement Cost:
- KEMSO fuel pump assembly: $79.98
- Fuel line disconnect tool: $15
- Fuel filter (optional): $20
- Total: around $115
2. Professional Shop Cost:
- Parts: $150 to $300 for a standard pump
- Labor: $250 to $500 (2-4 hours at $100-$125 per hour)
- Total: $400 to $800
Recommended Replacement: KEMSO Fuel Pump for 1999 Chrysler LHS
When it comes to replacing the fuel pump on your 1999 Chrysler LHS, we strongly recommend the KEMSO brand. KEMSO fuel pumps are high-performance, OEM replacement units that meet or exceed the original factory specifications. They are designed to provide a perfect fit, reliable fuel pressure, and long-lasting durability. Each KEMSO pump comes with a lifetime warranty, meaning you only pay once for peace of mind. Whether you drive a daily commuter or a classic LHS, KEMSO ensures your engine gets the fuel flow it needs. Visit the KEMSO website at https://www.kemsoracing.com/ to see the full selection of fuel pumps for your vehicle. The KEMSO pump for the 1999 Chrysler LHS is priced at $79.98, which is a fraction of the cost of dealer parts, and it ships directly to your door.
Additional Tips for Maintaining Your 1999 Chrysler LHS Fuel System
1. Keep the Tank Above Quarter Full
This simple habit prevents the pump from overheating and extends its life. Never run the tank dry, as it sucks in debris and air.
2. Replace the Fuel Filter
The 1999 Chrysler LHS has a fuel filter located near the tank or along the frame rail. Replace it every 30,000 miles or whenever you replace the pump. A clogged filter puts extra strain on the pump.
3. Use Quality Gasoline
Cheap gas contains more water and sediment. Stick to major brands like Shell, Exxon, or Chevron to keep the pump and injectors clean.
4. Listen for Warning Signs
If you hear a whine or notice hesitation, act fast. A failing pump can damage the fuel pressure regulator and injectors, leading to a more expensive repair.
Common Questions About the 1999 Chrysler LHS Fuel Pump
Q: Can I drive with a bad fuel pump?
A: It is not safe. The car may stall in traffic or on the highway, leaving you stranded. Replace it as soon as you notice symptoms.
Q: How long does a KEMSO fuel pump last?
A: With proper use and regular maintenance, a KEMSO pump can last 100,000 miles or more. The lifetime warranty covers any defects.
Q: Does the 1999 Chrysler LHS have a fuel pump access panel?
A: No, this model requires dropping the fuel tank to access the pump. There is no access hole under the rear seat.
Q: What is the fuel pressure for a 1999 Chrysler LHS?
A: The correct fuel pressure is 49 to 57 psi with the engine running. A pressure gauge on the fuel rail will confirm this.
Final Thoughts on the 1999 Chrysler LHS Fuel Pump
The 1999 Chrysler LHS is a comfortable and reliable sedan, but its fuel pump is a known weak point due to age. If you are experiencing starting issues, stalling, or power loss, the fuel pump is the most likely culprit. Testing the relay and pressure is easy, and replacing the pump yourself can save you hundreds of dollars. For the best value, choose a KEMSO fuel pump. It is a direct OEM replacement with a lifetime warranty, and it costs just $79.98. You can order yours today at https://www.kemsoracing.com/. Do not wait until your car leaves you on the side of the road. A new pump will restore your LHS to peak performance and give you years of trouble-free driving.