PAT


suppliers


aaaa logo

Member of Australian Automotive Aftermarket Association

PRTC Council Member

4WD Council Member



Latest News

Fault Finding Fuel Pressure Regulators (FPR)

What a technician needs to know about the various effects on the engine management system and how to correctly carry out a diagnosis and identify the results when the FPR becomes faulty.

Note: Refer to previous FPR article for Fuel Pressure Regulator types and operation for the various fuel supply systems.

Typical vacuum affected FPR operation.

Simplified typical common faults associated with an FPR fitted to a standard EFI system.

Generally, when a typical FPR fails, the result will generally create a:

  • Leaner than normal mixture due to an incorrect lower than normal pressure created by a sticking (open) internal FPR valve, an incorrect FPR unit fitted or a perforated diaphragm on an FPR unit that is located internal of the fuel tank.
  • Richer than normal mixture due to an incorrect  higher than normal pressure created by a sticking (closed) internal FPR valve, incorrect FPR unit fitted or a perforated diaphragm on an FPR unit that is located external of the fuel tank (generally on the fuel rail) and transferring the leaked fuel to the intake manifold via the vacuum hose. (also causes a hard to start condition due to excess fuel).

  • Delayed engine start up due to the loss of residual fuel pressure and fuel stored in the fuel lines caused by a leaking check valve seat in FPR allowing the fuel to drain back to the fuel tank.

Simple tests to be carried out to assist in determining if the FPR is causing incorrect mixtures.

When a diagnostic procedure is to be carried out on a vehicle that has performance issues, the technician needs to determine the correct cause/s to eliminate continuous parts replacement due to inconclusive diagnosis.

Typical fuel mixture related fault codes that can be problematic in the engine performance diagnostic process are typically (P0171 and P0174). Both codes relate to lean running / fuel mixture conditions for Bank 1 (P0171) and Bank 2 (P0174).

There are of course multiple causes for these codes and the technician requires a systematic approach to determining the cause.

Typically, the symptoms that the vehicle would exhibit are:

  • Increased fuel consumption
  • Check Engine Light will illuminate
  • Rough or high idle
  • Decreased acceleration
  • Engine stalling

Typical tests to be carried out to assist the technician:

Perform a fuel pressure test.

Correct fuel pressure and flow must be verified prior to carrying out further tests. Only after these fuel tests have been confirmed as being correct, would the other tests need be carried out.

Other Tests

Typically:

  • Check the intake system and vacuum lines for leaks
  • Inspect the valve cover for worn hoses or leaks
  • Inspect the PCV valve
  • Test the Mass Air Flow (MAF) sensor with a scan tool or multimeter
  • Test the related Oxygen (EGO) Sensor with a scan tool or multimeter

There are of course many other possible causes for these codes that would require further testing.

Typically:

  • Failed Fuel Injector (INJ)
  • Faulty Control Module or fault codes
  • Exhaust leak or faulty intake manifold
  • Outdated PCM software or faulty code reader

A rich mixture causing performance and stalling problems may log fault codes P0172 and P0175.

Again, the causes of these fault codes may be due to multiple component or system conditions and monitoring short term (ST) and long term (LT) trim using a suitable scanner can assist the technician in quickly determining the area of fault. These faults may cause intermittent rich mixture conditions or constant rich mixture conditions.

A typical scanner screen indicating an intermittent rich mixture and displaying the short trim reading of -17. (That is reducing the fuel by 17% at this point to try to maintain a correct fuel mixture). The simple oxygen sensor test also indicates a high voltage / rich mixture (807 mV).

This vehicle was fitted with an FPR with a perforated diaphragm that caused the intermittent richer than normal mixture. Removing the vacuum hose from the FPR generally quickly presents the technician with the evidence of fuel.

The ST trim reading varies depending on the amount of fuel that escapes past the FPR diaphragm.

The Premier Auto Trade Fuel range includes almost 150 Fuel Pressure Regulators (FPR’s) from the world’s leading manufacturers, covering almost 5.5 million vehicle applications in Australia and NZ.

When you supply and fit products from Premier Auto Trade you can expect a product designed and tested to the vehicle manufacturer’s specifications offering OE form, fit and function. Premier Auto Trade distributes products throughout Australia via a network of specialised resellers and leading automotive groups.



Latest News

Tech Tips - Wheel Speed Sensors (WSS)

Positive Crankcase Ventilation (PCV) and Oil Separators

Common Rail Diesel Pumps (HDP)

Exhaust Gas Temperature Sensor (EGT)

Hose Clamps

MAP Sensors (Manifold Absolute Pressure)

Electric Water Pumps

Pulse Width Modulation (PWM)

Mass Air Flow Sensors (Hot Wire/Film)

Petrol Fuel Injector Replacement

Electronic Throttle Bodies (TBO)

Dual Petrol Injection Systems – Technical Tip

Wheel Speed Sensors – More than just ABS

PAT Expands Emission Sensor Range

PAT Racing & Performance Injector Range Upgrade

Coils ain’t Coils!

ICON SERIES Range Grows

Oil Level and Oil Temperature Sensors Operation

Failed Air Temperature Sensors Symptoms

MAP Sensors Testing

TI Automotive Mustang Performance Pump

New ICON SERIES Hose Clamp Range

New Premium Sensors Ranges

Relay problems on vehicle

Test Equipment and Tools

Fuel Rail Sensors (FRS)

Failing Secondary Ignition

Testing Electric Fuel Pumps

Performance Fuel Rails and Filters

Testing CAM Angle Sensors (CAM)

Testing Electric Valve Solenoids (EVS)

Electronic Throttle Bodies

Performance Fuel Cells & Surge Tanks

Fault Finding Fuel Pressure Regulators (FPR)

Testing Variable Camshaft Actuators (VCA)

Testing Accelerator Pedal Position Sensors (APS)

Diagnosing Crank Angle Sensors (CAS)

Performance Regulators and Gauges

Differentiating Wheel Speed Sensors (WSS)

Mass Air Flow Sensors - Hot Film

Mechanical Fuel Pumps (MFP)

ICON Series Hoses

Particulate Matter Sensors (PMS)

Performance Fuel Injectors

Fuel Injectors (GDI)

DENSO Spark Plugs

Performance Fuel Pumps

Cooling Fan Switches (CFS)

Water Temperature Sensors (WTS)

Reverse Light Switches

Oil Temperature Sensors (OTS)

BMC Air Filters

Flasher Cans

Exhaust Pressure Sensors (EPS)

Power Steering Switches

Coolant Temperature Sensors (CTS)

Variable Intake Manifolds (VIM) and Intake Control Valves (ICV)

Oil Level Sensors (OLS)

Throttle Position Sensors (TPS)

Air Temperature Sensors (ATS)

Ignition – Condensers, Contact Sets, Distributor Caps and Rotors

Fuel System Accessories (FSA)

MAP Sensors (MAP)

Relays (REL)

HALL Sensors and Pickups (HAL)

Fuel Rail Sensors (FRS)

Speed Sensors (SPS)

New ICON Series Fuel Pump Range

New ICON Series Hose Range

Performance Range Increase Continues

PAT Oxygen Sensor Range Expands

PAT Expands Automotive Aftermarket Presence

Equipment and Tools

Electric Fuel Pumps (EFP)

Electric Valve Solenoids (EVS)

CAM Angle Sensors (CAM)

Ignition Modules (MOD)

Injector Service Components

Exhaust Gas Temperature Sensors (EGT)

Throttle Bodies

Knock Sensors

Ignition Coils

Fuel Injectors (Petrol)

Variable Camshaft Actuators (VCA) Oil control Valves

Accelerator Pedal Position Sensors (APPS)

Exhaust Gas Recirculation Valves (EGR)

Relocation of Sydney Distribution Centre

Wheel Speed Sensors (WSS)

High Tension - Ignition Lead Sets (ILS)

Suction Control Valves (SCV)

Mass Air Flow (MAF) Sensors

Crank Angle Sensors (CAS)

Fuel Pressure Regulators (FPR)

Oil Pressure Sensors

Exhaust Gas Oxygen Sensors

Shedding Light on Stop Light Switches

Ignition Distributors

Common Rail Diesel (CRD) Fuel Injectors

Idle Speed Control

New Distribution Centre Opening in ADELAIDE

New Distribution Centres Opening in PERTH and DARWIN

New Fuel Catalogue from Premier Auto Trade

BMC 4WD Air Filters Range Expands

New MVP Fuel Injector Range

PAT Developing Programs on Demand

New Premium Packaging for PAT

New Product Ranges Released By PAT

PlusQuip Test Equipment Range Expands

New Raceworks Catalogue

New Exhaust Gas Temperature Sensors

New Trade Catalogues from Premier Auto Trade

New Distribution Centre Opening in Adelaide

More European Parts from Premier Auto Trade

New PlusQuip Fuse Current Tester

PAT Pumped up!

Coils ain't Coils!

New PlusQuip Electronic EGR, Throttle Body, and Actuator Tester

New breed of High Performance products!

New Ignition Coil and Lead Set Kits

Wheel Speed Sensor Program Launched

Premier Ignition Lead Program Launch

Ignition Coils - Coils ain't Coils!

PlusQuip Battery Testers Launch

Premier Auto Trade Supporting Local Racing

Oval Trumpet Airbox (OTA) for 4WD applications from BMC Air Filters

BMC Air Filters NOW AVAILABLE from Premier Auto Trade

Premier Ignition Coils

MAP-013 and KNS-021 Now Back in Stock

BMC Air Filter partners with Premier Auto Trade

Premier Auto Trade opens South Australian Distribution Centre

Direct Fit Oxygen Sensor Range Hits 700

Automotive Electro-Mechanical Relays Types / Faults / Diagnosis

PlusQuip Tools and Equipment Launch

PlusQuip Fuel Line Repair Kit

PlusQuip Fuel Injector Service Kit

E85 High Performance with Premier Auto Trade

Testing EGR Systems (Pt 2)

New Delphi Fuel Module and Ignition Coil Range

Fuel Injector Service Components from Premier Auto Trade

Older News...

   privacy statement   terms of use   terms and conditions   sitemap   news  

© PremierAutoTrade