You Can Tune a Carburetor, but You Can’t Tuna Fish
I don’t know where the term “master engine tuner” originated, but I suspect it parallels that of “master piano tuner” because both disciplines transform apparent discord into apparent harmony. In this day of electronically managed engines, we forget that mechanically controlled spark advance curves and carburetor mixtures don’t compensate for changes in barometric pressure and
Diagnostic Solutions: Air/Fuel Ratio Sensors
Diagnose and Solve the Root Cause of Sensor Failure Before Sensor Replacement
The ABS Phenomenon: Profitability Hinges on Solid Preventive Maintenance Program
Profitability Hinges On Solid Preventive Maintenance Program An unusual event happened last week: a customer actually wanted a glowing warning light on his anti-lock braking system diagnosed! A preliminary interview revealed that: a) the ABS warning light was continuously illuminated, b) the brakes pulled to the right, and, c) the brake pedal pulsated when pressure
Diagnostic Solutions: Exhausting the Possibilities…Performance Upgrades
Depending upon the market to which an import shop might be catering, the term “performance exhaust” can have two different meanings. The first market actively seeks out the throaty rumble and chrome-plated look as part of the street-driving scene. The second market installs an exhaust system that produces the most horsepower for a performance application.
Diagnostic Dilemmas: Servicing Quadrajet Carburetors
src=”/wp-content/uploads/Articles/05_01_2008/39766Carb4jpg_00000021239.jpg” border=”0″ ” align=”right” alt=”photo 4: float level can easily be measured on the quadrajet.”/>can be measured by inserting a special Kent-Moore float level gauge into the bowl vent located just aft the choke valve. See Photo 4. Measuring the distance from the top of the bowl vent to the float and then subtracting the
Diagnostic Solutions: Charging System Diagnostics & Troubleshooting
Although checking charging voltage at the battery terminals is the most popular method for testing an alternator, a charging voltage test seldom reveals less common problems like open or shorted alternator diodes, intermittent high or low charging rates, charging system wiring problems, intermittent cranking/no start complaints or intermittent dead battery complaints. In addition, testing charging
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: Noise, Vibration & Harshness Diagnosis
Since the earliest days of the automotive service business, “squeak and rattle” diagnostics has become a euphemism for low-profit, nuisance repair work. Unfortunately for those of us in the auto repair business, even our best customers have the occasional need for noise, vibration and harshness (NVH) diagnostics. On the plus side, if NVH diagnostics are
Carburetor Tuning Through the Years
The modern “square” design of Holley carburetors was popularly introduced during the late 1950s. Because this style of Holley carburetor featured a simple, modular design with interchangeable parts and a great degree of adjustability, it immediately found favor with performance enthusiasts. In this story, we’ll use the Holley 4150-series carburetors to illustrate how to select,
Diagnostic Solutions: Disc Brake Caliper, Inspection and Installation Procedures
The repair or replacement of disc brake calipers has always been a controversial topic for most import shop owners and brake technicians. Some recommend replacing the brake calipers along with the brake pads, while others won’t replace the calipers unless they’re found to be defective. For many, routine caliper replacement is a cost issue and
Diagnostic Solutions: Transmission Electronics…Contined Refinement of Electronically Controlled Transmissions Shifts Fuel Efficiency into High Gear
Electronic automatic transmissions have gained popularity in recent years because of the flexibility that on-board electronics can provide in the area of powertrain management. Electronic transmission controls, for example, have done away with the rough, imprecise shifting patterns inherent in early mechanically controlled transmissions. With the continued refinement of electronically controlled automatic transmissions, an automatic
Puzzled by Carburetors
Although it’s hard to believe that nearly 20 years have passed since the last carburetor was installed on a mass-produced vehicle, carburetors are still the fuel system of choice for many off-road, street performance and track racing enthusiasts. In response to the performance market, aftermarket fuel system companies are now selling newly designed carburetors, updated