fuel Archives - Page 3 of 3 - UnderhoodService
Using Fuel And Ignition Waveforms Together

Fuel injector and secondary ignition waveforms can show the condition of the fuel and ignition system, and combined they can give you new insights on misfires and if they are related to the fuel or ignition system. Scan tools can tell you if there is a misfire and which cylinder is misfiring. Rarely will you be able to determine if it is the ignition coil and spark plug or if the fuel injector is causing a rich or lean condition. With a scope that has the correct probes, it is possible.

VIDEO: Negative Fuel Trim And Fuel Economy

Andrew Markel introduces a case study where a 2004 Chevrolet Impala has no codes, but is getting bad fuel economy. Sponsored by ProDemand from Mitchell1.

Hyundai Fuel System And Emissions Diagnostics

Bob Dowie recently had a 2002 Elantra GLS in the shop. This vehicle is a good example of some common fuel trim and emissions problems you’ll see.

Finding Failing O2 Sensors

Oxygen sensors are some of the most often replaced sensors. Inputs from the O2 sensors are used by the engine management system to adjust the fuel mixture. This is critical for maintaining low emissions and good fuel economy. If an O2 sensor gets “lazy” because of old age or contamination, the computer may not be able to adjust the fuel mixture quickly enough as the engine’s operating conditions change. O2 sensors that are failing tend to read lean, which causes the fuel system to run overly rich to compensate. The result is increased emissions and fuel consumption.

Oxygen sensor
Going Faster In 1954

According to most hot rod historians, nitro’s first competition use in America was by Vic Edelbrock Sr. and his associates. In the late 1940s, Midget racer Ed Haddad came into Vic’s shop with a gallon can of nitromethane he’d been given by one of the Dooling brothers, who manufactured slot cars (the tethered miniature cars that ran on a circle track popular in the 1940s and 1950s). Ed didn’t want any part of the new fuel because he had heard “it will blow up in your face.”

Diagnosing An Intermittent, Poor-Run, Hard-Start Complaint That Stumped The Local Body Shop

This month we’re going to be looking at an intermittent poor-run, hard-start complaint on a 2012 Hyundai Sonata. This car came to us by way of a body shop with which we work closely. Like most good working relationships, we are always willing to help these guys with our expertise, and they are wonderful about

2013 Hyundai Sonata
Tech Tips: Fuel Pump Float Arm Assembly

In some cases, float arm assemblies have been damaged after the fuel pump has been tested. Shipping, mishandling and pump insertion/removal from packaging are causes for potential damage.

Float arm assembly diagrams
Danger, Will Robinson! Intermittent Loss Of Power

This month’s Diagnostic Dilemma turns the page back to September 10, 2015 when I got a phone call from a local undercar shop inquiring if I had the tools to check the ECM connector pin fit on a 2012 Chevrolet Impala with the flex-fuel, 3.6L gasoline direct fuel injection engine. In response to an intermittent loss of power complaint, the shop had found a technical service bulletin (TSB) indicating that loose PCM connections can cause a loss of fuel pressure on the GDI engine’s high-pressure fuel rail and set codes P00C6 and P228C.

Three lobe cam for fuel pump
Detergents For Modern Vehicles

As a technician, it is hard to gauge a consumer’s gas-buying habits: Some owners may use a cell phone app to find the cheapest gas, while others habitually buy gas at one or two stations. No matter the type of customer, some in-tank fuel cleaners can help to alleviate fuel system and carbon buildup issues. Selling these fuel system cleaners in association with other maintenance services, like oil changes, is cheap insurance against cheap gas.