The fuel system uses a fuel pump, fuel filter, fuel injectors, fuel rail, and pressure sensor to run a modern internal combustion engine successfully. All these parts play an important role in the successful operation of the engine and supply the proper amount of fuel for adequate combustion. Similarly, the fuel rail pressure sensor also plays an important role.
But when the fuel rail pressure sensor goes bad, the operation and performance of the engine are adversely affected. When the fuel rail pressure sensor goes bad, you may experience several symptoms.
What Is Fuel Rail Pressure Sensor?
The fuel rail pressure sensor is a vital component in the fuel system, as it measures the fuel pressure circulating within the fuel rail and transmits its information to the engine control module.
The vehicle’s ECU determines the proper fuel mixture and ignition timing based on this data and ensures that the engine receives fuel in the correct amount and timing for efficient combustion. Typically, the fuel rail pressure sensor is installed at one end of the fuel rail.
Symptoms Of A Bad Fuel Rail Pressure Sensor
Whenever the fuel rail pressure sensor goes bad or the wiring to the sensor gets cut, some of the signs and symptoms of its failure are as follows:.
1. Check Engine Light Illuminates
When there is a problem or failure with any of the sensors, the check engine light on the dashboard illuminates. This is just a warning sign. To find out the actual reason why it illuminates, you will need to scan your vehicle’s system with the help of an OBD scanner.
Scanning the vehicle’s systems with an OBD scanner will help you figure out why the check engine light is on. However, sometimes a software error may cause the check engine light to come on, which can be reset by disconnecting and reconnecting the battery cable for 5 to 10 minutes.
2. Engine Not Starting
Sometimes the engine does not start if the fuel pressure sensor is faulty. A bad fuel pressure sensor is unable to signal a fuel pressure reading in the fuel rail to the engine control module.
Thereby the engine control module turns off the power pulse to the sensor on the fuel injector and the fuel injector stops injecting fuel into the internal combustion chamber of the engine. Therefore, the engine does not start even if the engine is cranked for a long time.
3. Long Cracking Engine Starting
In some cases, the engine starts very hard due to a bad fuel pressure sensor. This causes the ECM to send the wrong amount of fuel to the fuel injectors at the wrong time. Due to this, the fuel mixture in the engine is not ignited in the right amount or according to the position of the piston.
Due to this, the fuel combustion process in the internal combustion chamber of the engine gets disrupted. Hence, a bad fuel pressure sensor causes the engine to start loudly after cranking for a long time. However, these symptoms can also occur if the crankshaft and camshaft sensors are bad.
4. Engine Hunting Issue
The most common symptom of a bad fuel rail pressure sensor is engine hunting. A bad fuel pressure sensor can cause the engine speed to fluctuate constantly. Because a bad fuel pressure sensor is unable to signal the correct fuel pressure reading in the fuel rail to the engine control module.
The vehicle’s ECU starts sending more or less fuel to the fuel injector without a signal, causing the engine speed to continuously fluctuate up or down even at idle.
Sometimes the engine even starts hunting when the output of the alternator to the engine is high or low. Therefore, you must first check the causes of the engine.
5. Rough Idle
A faulty fuel rail pressure sensor in your vehicle’s engine may cause a rough idle problem and the engine will start at an abnormal speed at idle.
Additionally, when the engine is started at idle, the RPM needle on your vehicle’s cluster meter will begin to move up and down.
6. Engine Misfires
A bad or faulty fuel rail pressure sensor can also cause the engine misfires when accelerating. Due to a bad fuel rail pressure sensor, the engine control module of the vehicle is not able to send fuel to the fuel injector in sufficient quantity and with the correct timing.
Engine acceleration requires more fuel and proper ignition timing. But a bad fuel pressure sensor causes the ECM to be unable to complete the fuel firing order according to the engine speed.
Due to this, symptoms of misfiring start appearing in the engine during acceleration. However, there can be many other reasons for engine failure.
7. Low Engine Performance
A reduction in engine performance may be experienced due to a bad or faulty fuel rail pressure sensor. Because a faulty fuel rail pressure sensor is not able to send an accurate measurement of fuel pressure to the engine control module.
As a result, the ECM is not able to send the power pulse with the correct timing and the correct amount of fuel to the fuel injector according to the position of the engine’s pistons.
Due to which the fuel combustion process in the internal combustion chamber of the engine gets disrupted. Due to which sufficient amount of fuel is not burnt. Therefore, a loss in engine performance may be experienced due to a bad fuel pressure sensor.
8. Fuel Injector Knocking
Often a worn or faulty fuel rail pressure sensor in a diesel vehicle engine will cause the fuel injector to knock or continuously knock during acceleration. Because the fuel pressure signal is not being received by the ECM in the fuel common rail of the bad fuel pressure sensor.
Due to this, the ECM does not send power pulses to the fuel injector according to the fuel pressure, causing high fuel pressure to clog the fuel injector and cause the fuel injector power sensor to not function properly.
Fuel Rail Pressure Sensor OBD Codes & Meanings
- P0190 – “Fuel Rail Pressure Sensor Circuit Malfunction”
- P0191 – “Fuel Rail Pressure Sensor “A” Circuit Range/Performance”
- P0192 – “Rail Pressure Sensor A Circuit Low Input”
- P0193 – “Rail Pressure Sensor A Circuit Low High”
- P0194 – “Fuel Rail Pressure Sensor “A” Circuit Intermittent/Erratic”
Fuel Rail Pressure Sensor Replacement Cost
Fuel pressure sensor replacement cost depends on the make and model of the vehicle and the location of the mechanic to perform the replacement.
On average, the cost of a replacement fuel rail pressure sensor for common vehicles can range from $160 to over $260. This cost may include the mechanic’s labor costs. A fuel pressure sensor can cost $100 to $150, and the labor cost to have it replaced by a mechanic can range from $60 to $110.
FAQ’s
Given below are some useful and user FAQs related to Fuel Rail Pressure Sensor, which will be help in making this article useful content.
What Are Symptoms of A Bad Fuel Rail Pressure Sensor?
If the fuel rail pressure sensor is bad or any of its wiring is damaged, symptoms may include an illuminated check engine light, engine failure, prolonged crackling, engine misfire, rough engine idle, fuel injector knocking, or poor engine performance.
Where is The Fuel Rail Pressure Sensor Located?
Generally, in most vehicles, the fuel rail pressure sensor is located on the right or left end of the fuel rail.
How Do You Check Fuel Pressure Sensor?
To check the fuel pressure sensor, first disconnect the fuel sensor wire connector. Now start the engine. However, your vehicle’s engine may now start with a prolonged crank. Connect the fuel pressure sensor lead to the multimeter lead. Check the fuel pressure reading on the multimeter with the engine running.
How Much Does it Cost To Replace The Fuel Pressure Sensor?
Fuel pressure sensor replacement costs for vehicles can range anywhere from $160 to $260. This cost includes the labor cost of having the fuel pressure sensor replaced by a mechanic.
What Happens When Fuel Rail Pressure is Low?
A broken or failing fuel pressure sensor can cause a variety of symptoms in a vehicle. such as engine misfire, engine vibration, engine stalling, acceleration hesitation, and low power performance.
