Here are 5 Signs Your Fuel Pump is Not Reliable (and How To Replace it)

A vital component in your vehicle's fuel system, the fuel pump relay.

When it's time for fuel pressure to build up, the fuel pump relay provides power. When you turn on the ignition, the fuel relay will be activated.

Fuel pump relay failure can be caused by many different factors. This article will explain how to identify if the fuel pump relay has failed, what it looks like, where to find it and its cost to replace. Let’s begin with a quick overview of the signs to look for.

5 Bad Fuel Pump Relay Symptoms

Stalling, or dead engine, is one of the main symptoms that a fuel pump relay has failed. These signs will likely be accompanied by a check engine lamp on your dashboard. Additionally, you might notice rough acceleration.

A fuel pump relay's health can be affected by many factors, such as dust or electrical power surges.

This is a detailed listing of symptoms that indicate a bad fuel pump relay.

1. On the Engine Light

Engine control modules monitor all sensors in order to prevent them from showing wrong values. When the ECU senses that a sensor is showing a false value, the engine control module will turn on the check engine lamp. The most obvious sign that a fuel pump problem is present, a check engine light.

With the aid of the fuel pressure sensor, the ECU monitors fuel pressure. The ECU will store trouble codes on fuel pressure and light the check engine lamp if the fuel pump relay fails suddenly.

RELATED: Signs that a Main Relay is Bad

2. Rapid Acceleration

The fuel pump relay going bad can affect the fuel pump’s power and affect fuel delivery to the engine. Just like the engine that runs on fuel is powered by oxygen or blood, an engine also runs on fuel.

Fuel pump relay problems can cause fuel to stop flowing into the combustion chamber and may result in your vehicle not starting.

This can also be caused by other factors, like a clogged fuel filter. Before you replace any part, make sure to properly inspect your vehicle.

3. Engine Stalling

Bad solderings may cause the fuel pump relay to lose its connection, and it could stop providing power to the pump.

The engine turns off if the combustion chamber’s fuel is inadequate or doesn’t have the proper pressure.

It is the fuel pumps that prevents this from happening. The fuel pump relay can have problems and the pump will cease to function properly.

4. The engine is dead

Failing fuel pump relays can cause your engine to not start or be totally dead. An engine that has no fuel pressure will stop starting. A faulty fuel pump relay can also cause the engine to not start.

5. There is no sound from the fuel pump when it's on.

You should hear the car making a loud whirring sound when you switch the ignition off in the ignition lock. The fuel pump has started to build fuel pressure within the fuel rail.

You might have a problem with your fuel pump relay if you don't hear it. After turning on the ignition, you can listen closely to the fuel tank and hear any unusual noises for about 2-3 seconds.

Is the fuel pump relay located where?

The fuel pump relay can be found in most cars in a fusebox under the dashboard. However, it is also possible to find it in the fusebox in the engine bay.

The engine’s or the dashboard fuse box is usually a long black box containing a fuel pump relay and various other fuses and relays. Different vehicles may have different fuel pump relay locations.

For the fastest location, consult your manual.

Price of a Fuel Pump Relay Repair

Depending on your car's model and labor cost, the average fuel pump repair costs are between $90 to $150. Parts can cost between $20 to $50 and labor may add up.

A fuel pump relay can be purchased online. The fuel pump relay’s replacement cost involves the cost for the parts and the labor cost that the mechanic would charge you.

Consider the labor costs. It might be as low as one hour, but it can go higher in some cases.

Depending on your mechanic’s hourly pay rate or the per hour cost, the repair shop would charge you; the labor cost may differ. The fuel pump relay, aside from its labor costs, is relatively inexpensive and can be purchased for between $20-$50 for most cars.

Diagnosis of the Fuel Pump Relay

It is usually easy to diagnose a relay. It is common for fuel pump relays to have four pins. This makes it easy. A wiring diagram is needed if the relay contains more pins that are not listed.

1. Find the fuse box, and the fuel pump relay.
2. It can be lifted and checked for numbers 30, 85, 56, and 87. You can replace the fuel pump relay if you find these numbers.
3. Reverse the relay so that you can access the pins while cycling the ignition.
4. With a multimeter, check pin 87 by turning on the ignition. It may indicate that your fuel pump relay works, or it could be intermittently malfunctioning.
5. You should ensure that the voltage is constant on Pin 30, with the ignition switched on, if you don't get it. If you don’t, there might be a problem with a broken fuse. Also, pin 85 should have constant voltage and pin 86 should always be grounded to the engine control unit before you switch on the ignition.
6. To check for soldering problems, remove the cover from the relay. Resolder the relay in case of any problem.

Commonly Asked Questions