March 2014 Archives - UnderhoodService
10 Signs A Fuel Injector Needs To Be Replaced

In the past 30 years, the fuel injector has moved from the intake manifold to the combustion chamber. During this evolution, injectors have become more precise in dispensing fuel. If this precision is thrown off by restrictions, electrical problems or fuel problems, it can cause driveability issues. These are the top 10 signs fuel injectors need service or replacement.

Snap Test: MAF Sensor Diagnostics

You’d think a service light would be the first indicator of a mass air flow (MAF) sensor problem, but there are times a problem develops with the MAF and no service light comes on. Scott “Gonzo” Weaver explains how poor idle, loss of performance, sluggish performance and even stalling are all associated with a failing MAF sensor.

Don’t Judge A Job By Its Cover

It was a picture perfect day at the auto repair shop until two new jobs showed up at the same time. A nice, clean 2007 Ford F-350 4WD diesel with an ABS light on, and a really dilapidated 1997 KIA with charging system problems and no light on. You’ll never guess how these two stories end.

Diagnosing Variable Valve Timing

Fully variable valve timing can be achieved only by using computer-operated solenoids to precisely control the intake and exhaust valve opening and closing events. Although the various combinations of valve timing events are theoretically infinite on an electronically controlled system, their applications are limited due to issues of cost and, in some cases, reliability.