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About Delphi Fuel Pressure Regulators.

Those smart designs, and rigorous testing and troubleshooting, have helped us create fuel pressure regulators and other fuel components that pass the tests of time, emissions standards and customer satisfaction.

Critical to Engine Function.

A fuel pressure regulator works to maintain proper and consistent pressure for the injectors during a variety of driving conditions. Pressure that is too high can cause misfiring and increase vehicle emissions. Low pressure can cause poor vehicle performance and slow — or no — starts. Both high and low pressure can reduce fuel efficiency and even shorten the life of the engine. A leaky fuel pressure regulator diaphragm often causes lower fuel pressures, but the problem can be tricky to diagnose. Regulator issues are often misdiagnosed as an oxygen sensor problem, and can cause multiple, misleading OBD II codes.

Smooth Performance and Comprehensive Coverage.

Vehicle manufacturers have relocated fuel pressure regulators from the fuel rail in the engine compartment to the tank, which keeps fuel temperatures lower and cars running more efficiently. Our OE design enhances fuel control accuracy for smooth driving and emissions performance that will keep your customers happy. Delphi uses exclusive NitrileTM nylon fabric diaphragms, which are strong and resilient against corrosive, high-ethanol fuels.

Our fuel pressure regulators are available in two different designs--universal pressure and mini-cartridge pressure--for wide coverage of domestic vehicles on the road today.

All Delphi mini-cartridge regulators are 100% flow tested and the pressures are factory calibrated. Six Delphi mini-cartridge part numbers represent more than half the sales volume on GM applications, which helps streamline your inventory and reduce your investment.

The Delphi Difference

100 years of OE experience, supplier to the world’s top automakers
OE heritage and knowledge built into every aftermarket part
Comprehensive portfolio for a wide range of vehicles and model years
Streamlined SKUs for easy inventory management
Support through tools, tips and training

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2 min read

Common GDi service issues

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Fuel Injection Diagnostic Fuel Management Fuel Systems Gasoline Direct Injection (GDI) How to Shop Owners Technicians 2 min read

Resource Highlights

In this article you will find out about the basics of GDi and understand the common GDI service issues.

GDi pumps being manufactured by Delphi.

Basics of GDi

Despite making its debut in the mid 1950’s, Gasoline Direction Injection (GDi) has only recently come into its own, as vehicle manufacturers look for more meaningful ways to meet increasingly stringent emissions standards.

By injecting fuel at high pressure directly into the combustion chamber, the innovative system improves fuel atomization and penetration, delivering reduced CO2 emissions, improved fuel economy and better engine performance.

So why has a technology with so many good things going for it not been adopted sooner? The simple truth, is that like many things, there are pros and cons. And for GDi, that also means a number of common service related issues such as carbon build up, oil vaporization and low speed pre-ignition.

Understanding common service issues for GDi

Here we explore what these are and, importantly, how we can help you to overcome them.

Fuel dilution: Because the injectors are located in the combustion chamber, fuel spray can wash past the rings, down the far cylinder wall and into the oil sump, contaminating the oil and affecting its viscosity. This can cause issues such as increased wear of pistons, rings and cylinders, reduced protection against deposits, higher oil consumption and quicker oxidation.

Oil vaporisation: The higher temperatures and pressures in GDi engines can accelerate oil vaporization. Oil vapors passing through the cooler areas of the engine such as the intake valves, piston crown and catalytic system can lead to pooling and the formation of oil droplets. Because, unlike a port fuel injection engine, these droplets are not washed off by the fuel, they can coat and bake onto the valve causing performance issues.

Oil evaporation: The higher temperatures in the crankcase can also cause some of the oil to evaporate, meaning that the fuel can become more concentrated. Much like fuel dilution, this impacts the oil’s viscosity, accelerating wear and tear of key components and reducing the oil’s service life.

Carbon build-up: Again, because fuel no longer reaches and cleans the valves, this can result in a build-up of carbon on both the injectors and valves, restricting fuel delivery and air flow to the cylinders respectively. Over time, these deposits can cause performance issues such as reduced engine power and fuel economy.

Low-speed pre-ignition: Known as LSPI for short, it typically occurs under low speed, high load conditions. LSPI is caused by fuel droplets that are released into the combustion chamber and ignited before the spark plug fires. This abnormal combustion event can result in higher engine pressures, leading to engine knock and potentially severe internal damage.

As these service issues can occur in as little as 3,000 miles, diagnosing and remedying them early is important. Failure to do so will not only affect the vehicle’s performance and fuel economy, but if left untreated for long enough, could also result in severe engine damage, requiring a timely and costly teardown to fix.

The good news is, that as a leading manufacturer of OE GDi technology, we understand the challenges of maintaining and repairing these highly advanced, high pressure systems. And alongside the OE parts, provide the tools and know-how you’ll need to remedy these issues, long before they become a bigger problem.