Why Go Digital? For Precision and Protection
These days, no matter what kind of automotive repair work you specialize in, virtually every system has a certain amount of electronics. Consequently, one diagnostic tool every technician needs is a digital multimeter. To figure out electrical and electronic problems, you have to “see” what’s going on inside the circuits and components. Trouble is, you
How Sensors Provide ‘Good Input’ for Diagnostics
One of the systems that Subaru has perfected through improved reliability over the years has been its distributorless ignition system (DIS) for all of its models. Because of the horizontally opposed design of its engines, the ignition system can be centrally mounted and made simple. In this article, we will touch on some common diagnostic
Ford Timing Belts & Chains
Timing belt and chain replacement is one service that isn’t going away any time soon. Most Ford engines with overhead cam timing belts have a recommended replacement interval of 60,000 miles to 120,000 miles depending on the application (see the chart on page 54). So if a customer is driving a vehicle that is more
Mercedes-Benz Engine Diagnostics
I’ve always loved the puzzle. Check Engine warning lights have become an everyday chore for me over the last five years. It’s a challenge that extends my interest and creativity in the auto service profession. Before I deal with some specific Mercedes-Benz faults that I’ve researched, I must say that the ability to really solve
Selling Multi-Coil Ignition Parts
Time has indeed passed you by if you still believe in the traditional import engine tuneup. Many years ago, much of the import service market revolved around the annual spark plug, ignition cable, distributor cap and rotor replacement needed to maintain an import engine at peak efficiency. During the past decade, however, multi-coil waste-spark and
Mass Air Flow Operation Strategy
When diagnosing hot-wire air flow meters (A/F meters) on Subarus and similarly equipped Asian vehicles, technicians may find that, while the meter passes all recommended test procedures, the engine exhibits driveability conditions associated with lean air/fuel mixture ratios. In these cases, it’s best to form a diagnostic strategy based on the relatively simple operating principles
Head Gasket Replacement
During some point in their service lives, most import engines built with cast-iron cylinder blocks and aluminum cylinder heads will need a cylinder head gasket replacement. The vulnerability of aluminum-head engines to head gasket failure is caused by the aluminum cylinder head expanding approximately 1.5 times more than the cast-iron block. Although measured in thousandths
Understanding Today’s Multi-Coil Ignition Systems
Distributorless Ignition Systems (DIS) have been around for more than two decades, but in recent years the trend has been to multi-coil systems such as Coil On Plug (COP) or Coil Per Cylinder (CPC) ignition systems, and Coil Near Plug (CNP) ignition systems. COP systems have become the hot setup for a number of packaging,
Analyzing Ignition Misfires and Plotting a Diagnostic Course
Uh oh. The Malfunction Indicator Lamp (MIL) is on, and you’ve just found a misfire code. It’s a code P0304, which tells you cylinder number four is misfiring. There are no other codes and the engine has a steady miss. Now what? Misfire diagnosis in this kind of situation should be fairly easy. You have