Oxygen Sensors: Pulse Measurement
Watching an oxygen sensor output on an oscilloscope is like watching a sporting event on television. You get to see the action, but can do nothing about it as it happens. Sometimes you miss the action and want an instant replay. It was a bad call. You saw the interference. If the referee didn’t see
Diagnostic Solutions: Cylinder Head Service, Restoring the Engine to Precise OE Tolerances
Although cylinder head repairs have been a staple of the import repair shop for many years, modern technology has changed the way we should sell and perform cylinder head services. In years past, for example, a cylinder head repair need last only 30,000 or 40,000 miles until the vehicle was retired from service. Today, however,
Diagnostic Dilemmas: Temperature Tantrums
Solving temperature-related, no-code intermittent failures can be a frustrating experience for the diagnostic technician because the exact level of heat or cold needed to trigger the failure is often hard to duplicate. It’s also important to keep in mind that all electronic vehicle components are exposed to temperature extremes and thus are vulnerable to temperature-related
Who’s at Fault?…Top 10 Domestic Diagnostic Codes & Fixes
A Check Engine Light that’s illuminated is always a sign that something is wrong. But what? You usually can’t tell until you plug in a code reader or scan tool and read out the code(s) that have turned on the light. At least then you have a starting point for further diagnosis. Some people think
Scan Tools: Scan Tools Offer a Window Into a Vehicle’s Inner Workings
Scan Tools Offer a Window Into a Vehicle’s Inner Workings Larry Carley, Technical Editor [email protected] Technicians who attempt to make driveability or emissions repairs today without a scan tool are troubleshooting in the dark. A scan tool is absolutely essential because it provides a window into the inner workings of the engine management and onboard
Diagnostic Solutions: Fluid Maintenance…Selling Needed Services Vs. “Wallet Flushing”
Good import shop managers stay on top of their annual workflow by placing jobs like timing belt and brake replacements into categories that can be tracked on a historical basis. If a shop has faithfully tracked the kinds of work flowing through its service bays during the past 10 years, it might become apparent that
GMC/Chevy Light Truck: Central Port Fuel Injection Diagnosis
Back in 1992, General Motors introduced a new type of fuel injection system known as “Central Port Injection” (CPI), which GM also refers to as “Central Multi-point Fuel Injection” (CMFI). The system was used on 4.3L V6 Vortec engines through 1995, and was redesigned in 1996 and renamed “Central Sequential Fuel Injection” (CSFI). The system
Tech Info for Servicing Parts: Central Port Fuel Injection Diagnosis
The acronym PATS stands for Passive Anti-Theft System. It is called “passive” because it requires no action on the part of the driver. With this system, Ford likes to play annoying little games of PATS hide-and-go-seek. That is to say, they can’t seem to decide where they want to put the PATS system. Not only
TPMS: What are Dealers Doing?
Service shops aren’t the only ones concerned about TPMS these days. Auto dealers, also, are handling an increasing number of TPMS-equipped vehicles in their service bays. While there’s strong competition for vehicle service, TPMS is forcing both auto and tire dealers to cope with a new side dish on their service menus. The common thread,
Predicting Failures
spect that at one time or another, we’ve all had a customer return with a check engine light on with a new fault code that wasn’t there last time they were in. The events probably went something like this: Customer: “You couldn’t see that when you looked at it last time?” Shop: “No ma’am, there’s
Diagnostic Dilemmas: Symptom Diagnosis…The Journey Begins
When I first began my automotive career way back in 1957, the symptoms of an ailing engine were very apparent. A carburetor with a worn accelerator pump, for example, would characteristically stumble on acceleration and a closed-up set of distributor contact points would cause the engine to become very sluggish. Low fuel pressure caused by
Foreign Affairs: Getting Nissan Engines Back to Peak Performance
/Articles/06_01_2007/60754gif_00000014067.gif” width=”156″ height=”146″ alt=”” border=”0″ align=”right” /> In this article, we’ll take a look at some of the common problems that affect engine performance. With on-board diagnostics (OBD), many of these problems will cause a check engine lamp (CEL) and store a code. With most of us becoming comfortable and proficient while working with OBD