Cables act as highways through which electricity flows to the spark plugs. In time, they can fail. When they do, voltage needed by spark plugs to ig­nite the fuel mixture won’t reach the plugs, resulting in hard starting, missing, and/or rough idle. If the problem is severe, the engine won’t start. Read More… As time [...]

Most engines manufactured since the 1960s have a positive crankcase ventilation (PCV) system, which prevents hydrocarbon vapors in the crankcase from escaping into and polluting the atmosphere. The central component of this system is the PCV valve, which is a main concern when an engine begins to idle roughly and/or stall. Read More… Two other [...]

Engines equipped with electronic control systems, which are usually re­ferred to erroneously as computerized systems, have oxygen (O2) sensors that monitor the oxygen content of the exhaust. This includes all engines with throttle body and multiport fuel injection systems and some engines with carburetors. Read More… The oxygen sensor allows a microprocessor to adjust the [...]

The fuel system of an engine equipped with a carburetor uses one of three types of filters to trap contaminating material that may be present in gasoline because of dirt in the vehicle fuel tank or dirt in the tanks of gasoline stations. Dirt that enters the carburetor can block passages, im­peding the flow of [...]

Most engines have an exhaust gas recirculation (EGR) valve to help pre­vent the formation of oxides of nitrogen (NOx). NOx in the presence of sunlight forms smog. Read More… As fuel burns, temperature inside an engine can rise to a point at which it acts as a catalyst for nitrogen and oxygen molecules to fuse [...]

Most vehicles manufactured since the mid-1980s are equipped with halo­gen bulbs. If the bulb burns out, it can usually be replaced without replacing the entire headlight unit, because the bulb and headlight are separate. This is different from a sealed-beam headlight, where the light­ing filament (bulb) and the lens are integrated into a single unit. [...]

By following the procedure described in this article, you may be able to repair an automatic transmission that is slipping. “Slipping” is the term applied to a transmission that doesn’t shift gears at the proper time. The condition is identified by a lag in upshifting as engine speed increases. Read More… It is important to [...]