Injectors Archives - UnderhoodService
A Closer Look: Gasoline Direct Injection (GDI)

Gasoline direct injection (GDI) is used on most new vehicles and requires a different approach to diagnosis and service. GDI technology has been an integral part of helping to improve fuel economy while reducing emissions, and can be found on more than half of the U.S. fleet. In fact, the use of GDI engines has

VIDEO: Injector Balance Testing

If an injector is malfunctioning, an injector balance test may help. This video is sponsored by Standard Motor Products

VIDEO: Replacing All The Injectors

There are a few tell-tale signs of a faulty fuel injector. This video is sponsored by Standard Motor Products.

VIDEO: Solving The Carbon Deposit Conundrum

Carbon deposits can be formed by varying cylinder temperatures. This video is sponsored by Rislone.

The Duramax Dilemma: Injector Circuit Diagnostics

The owner of this GM Duramax was headed to Montana on vacation with his family and camper trailer in tow. After stopping for lunch, the owner was dismayed to find that his Duramax immediately went into “limp mode” as the engine started.

Clean Carbon From Intake Valves With Lang Tools Fuel Injection Cleaner

Lang Tools offers its Fuel Injection Cleaner (TU-470B) with two gauges that enable a technician to check the vehicle fuel pressure with the right-side gauge, and then easily set cleaning pressure with the left-side gauge by referring to vehicle fuel pressure on the right side gauge.

Fuel Pump Diagnostics: Using Scan Tools

The most common diagnostic procedures for fuel pumps in the past were analog and hands on. Most fuel pump-related problems could be solved with a pressure gauge and voltmeter. Today, the scan tool is the most important tool when diagnosing a fuel supply problem.

Diagnostic Solutions: Fuel System Pressure & Volume Checks

For maximum efficiency, modern import fuel injection systems require that fuel be delivered at a specified volume and pressure. Because the fuel injector’s job is to mix fuel with the intake air charge, it must produce a finely misted, conical spray pattern through the fuel injector nozzle. Lower-than-specified fuel pressures not only fail to provide enough fuel for combustion at larger throttle openings, but may also introduce an uneven air/fuel charge distribution into the combustion chamber itself, which usually results in hard starting, hesitation and reduced power output.

Fuel Pressure checks
10 Signs A Fuel Injector Needs To Be Replaced

In the past 30 years, the fuel injector has moved from the intake manifold to the combustion chamber. During this evolution, injectors have become more precise in dispensing fuel. If this precision is thrown off by restrictions, electrical problems or fuel problems, it can cause driveability issues. These are the top 10 signs fuel injectors need service or replacement.

Intake Manifold Gaskets: A Service Rundown

Back in the days when most

BMW Fuel System Repair Essentials

The BMW N54 fuel pump recall a few years ago brought to light the importance of the integrity of the fuel system and how it can contribute to the overall reliability of a vehicle. These fuel quality issues apply to all BMW vehicles with either port or direct injection. The underlying message here is that if the cleanliness and overall integrity of the fuel tank is ignored, it will damage any fuel pump. This is why addressing the fuel tank is essential during any pump replacement to prevent costly comebacks that can also hurt your reputation.

Diagnosing EGR And Secondary Air Systems

The perfect internal combustion vehicle would be able to put the exact amount of fuel and air into the combustion chamber. If the perfect combustion event happened, you would get nothing more than water and carbon dioxide. We are not there yet. In the mean time, we have exhaust gas recirculation systems (EGR), secondary air injection and catalytic converters.