Tech Tip: Diagnosing an Engine that Won’t Start
For any engine to start, three things are necessary: fuel, compression and spark. If any of these components is lacking, the engine won’t start. The fuel system must be generating normal fuel pressure, and the air/fuel ratio must be correct for the ambient temperature and engine temperature. If the air/fuel mixture is too lean, it won’t ignite and the engine won’t start. If the air/fuel mixture is too rich, it can flood the engine and also prevent it from starting ….
Tech Tip: Diagnosing Malfunctioning Jeep Instrument Cluster
The same two-wire CCD BUS that Chrysler has been using for years on its cars is now being used on Jeeps and trucks, giving today’s Jeep Wrangler a new level of sophistication. If the instrument cluster doesn’t work, first determine which gauges don’t operate or if the whole cluster is down. I like to start testing with the printed circuit board self test ….
Tech Tip: Engine Knocking Noise Just Above Idle May Be Normal
Engine "knock" may be heard on an applied vehicle just above engine idle speed (800-1,100 rpm) with the engine under a slight load. The noise cannot be detected over 1,100 rpm. The cause may be a normal pulsating noise coming from the EVAP purge solenoid valve and piping (in the engine compartment) transferring into the passenger cabin. However, use the following procedure to reduce the noise ….
Understanding Steering Quality
And Delivering a Good Driving Experience to Customers
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
Mode $06 Diagnostic Update
Mode $06 has been around since the introduction of second-generation onboard diagnostic (OBD II) systems back in the mid-1990s. Essentially, Mode $06 is the raw test data the OBD II system uses to evaluate the operating status of various components in the engine management and emission control systems
Finding the Failure Pattern
but that’s about it when it comes to diagnosing random, no-code malfunctions. Lucky or not, the chances of locating the cause of a random, no-code malfunction can be increased by determining the sequence of events needed to trigger the malfunction. Determining this sequence of events is what I call, “Finding the Failure Pattern.” From the
Tech Tip: Diagnosing Wheel Speed Sensors
Wheel speed sensors (WSS) provide essential wheel speed information not only for anti-lock brake systems (ABS), but also for traction control and stability control systems. Some vehicles even compare the wheel speed sensor readings against the vehicle speed sensor (VSS) to make sure all of these sensors are accurate and working correctly. In some situations, it is also possible that the ….
Diagnosing Intermittent Stalling Issues
Intermittent driveability problems of any kind are always a challenge to diagnose. When a customer brings you a vehicle and complains of a stalling problem, you may not have much to go on other than their description of what’s happening and when it happens. The more information you can get out of them the better,
Downloading Repairs
Have you looked at technical service bulletins lately? Especially ones for vehicles built since 2004? The fixes have changed drastically. I remember a time, not too long ago when the fix in a typical TSB was to install an updated part. From where I stand now in a Ford dealership, it seems like the hardware
Has Your Battery Life Lost Its Charge? Tips to Get Back That Spark
The condition of the battery as well as its state of charge are critical in late-model vehicles not only for reliable cranking and starting, but also for the onboard electronics. Low battery voltage can cause control modules to misbehave, or in some cases to go into a sleep mode and shut down. A dead battery
News: SPX Acquires Chinese Diagnostic Tool and Equipment Maker
From aftermarketNews Staff & Wire Reports Shanghai, China — SPX Corp.’s Service Solutions business unit has completed its acquisition of AUTOBOSS Tech Inc., a Shenzhen, China-based manufacturer of diagnostic tools and equipment. “This investment further underscores our commitment to accelerate growth and expand our business in strategic markets, China in particular,” said David Wilson, president