Tech Feature: Detecting Misfires in OBD II Engines
With OBD II, there’s no missing misfires. Most engine control systems with OBD II monitor the speed of the crankshaft between cylinder firings to detect misfires. The powertrain control module (PCM) notes the relative position of the crankshaft via the crankshaft position sensor (CKP) each time a trigger pulse is sent to the ignition system.
Tech Feature: Diagnosing the Blue Car Syndrom of a Random Stalling Condition
Blue Car Syndrome is the non-technical term for a very common phenomenon. It is the experience that many people possess regarding having a specific observation, idea, experience, etc., enter one’s consciousness, and then having it seem that the same observation or experience begins to occur with increased frequency.
Tech Feature: Engine Technology Gets a Boost
As a technician, you’ll need to understand how Ford’s EcoBoost turbocharged gasoline direct injection engine works, since the automaker plans to incorporate it in 90% of its new vehicles over the next three years.
Tech Tip: Multiple Cylinder Misfire or Rough Idle on Chrysler Models
This bulletin involves rotating all engine exhaust valves, replacing the valve spring retainer locks with a new design to increase valve rotation at lower rpm, inspecting/replacing the MAP sensor (as necessary), and decarbonizing the combustion
Jeep Fuel Problems Needn’t Be an Uphill Battle
The Jeep Grand Cherokee has been a dependable vehicle for many vehicle owners over the years. However, the SUV has had a few fuel system problem that has put Jeeps in repair shops. In this article, we’ll address some fuel system complaints that have plagued these vehicles.
Tech Feature: Diagnosing Repeat Fuel Pump Failures
During the past several years, I’ve encountered many vehicles that were running on their third or fourth new fuel pump in as many years. As with many repeat failures, the initial fuel pump installations were sloppy or a brand of fuel pump with a known high failure rate had been installed. In the remaining cases, an OE or aftermarket-equivalent fuel pump had been installed, but fuel tank contamination had been overlooked as a cause of the premature failure.
Tech Feature: Returnless Fuel Injection Systems
If you’ve tried to find the fuel pressure regulator on many late-model engines by looking in the engine compartment, you won’t find it there because the regulator has been relocated to the fuel tank. Engines with “returnless” electronic fuel injection (EFI) systems have the regulator inside the fuel tank. The regulator is part of the fuel pump assembly and is usually located downstream of the in-tank fuel filter.
Tech Tip: Diagnosing Fuel Pumps and Injectors
One of the first questions that should always be answered when diagnosing a fuel-related complaint on a fuel-injected engine is, "What is the fuel pressure?" All too often, technicians assume fuel pressure is "good" without actually measuring it with a gauge. If the engine runs, they assume the injectors are getting adequate fuel pressure. If the engine cranks but won’t start, and they depress the service valve on the ….
Tech Feature: Diagnosing Fuel Pumps and Injectors
One of the first questions that should always be answered when diagnosing a fuel-related complaint on a fuel-injected engine is, “What is the fuel pressure?” All too often, technicians assume fuel pressure is “good” without actually measuring it with a gauge. If the engine runs, they assume the injectors are getting adequate fuel pressure. If
Subaru Tech Tip: Diagnosing Idle Surges on Legacy Models
If you encounter a driveability concern such as idle surges or whistling, it may be caused by carbon buildup on the Idle Speed Control (ISC) valve. In these cases, it is not necessary to replace the ISC valve. Cleaning the ISC valve could correct the condition. To clean an ISC valve, perform the repair procedure ….
Fuel Injector Service: The Basics and Beyond
and go traffic conditions. Because high underhood heat usually increases electrical and clogging failures in fuel injectors, fuel-injected vehicles driven in metro areas may generally need more maintenance than vehicles driven in rural areas. We can also generally say that many late 1980s and early 1990s fuel injectors fail more often because of poor design,
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