How do I check An Engine Oxygen Sensor?

All engines run on an optimum fuel to air mixture called "stokiometric" which means chemically balanced. This balanced fuel to air ratio is 14.7 to 1, 14.7 parts air to 1 part fuel. The oxygen sensor is created using the active chemical such as zirconium, electrochemical (also known as Galvanic), infrared, ultrasonic and very recently laser. When a lean mixture code is detected by you or a technician the first tendency is to replace the oxygen sensor. The best way to check the operation of the sensor is to run a simple test. No matter if your engines
oxygen sensor has one wire or four there is only one sensing wire that feedbacks information to the PCM. To find this wire you will need a car repair manual. If a trouble code is present that pertains to an oxygen heater sensor failure, replace the sensor to repair the problem. An oxygen sensor must be warm before it will operate properly.

Warning: If a malfunction exists with related components such as an engine misfire or engine vacuum leak do not perform this test. The oxygen sensor is designed to operate within a particular range, if this range is exceeded the sensor will give the appearance that it has failed.

GM Oxygen Sensor - (appearances will vary)

Oxygen Sensor Test
Tools needed to perform these tests: Voltmeter

* Step 1 - Once the oxygen sensor sensing wire has been located connect a volt meter to the feedback wire and ground. Select the millivolt operation on the meter.

* Step 2 - Next, start and run the engine at idle until warm (about 15 minutes). Observe the voltmeter; it should bounce slightly at whatever voltage the sensor is centered at (about 150 millivolts).

* Step 3 - Continue to observe the meter and have a helper rap the throttle. The meter should drop for a split second as the mixture leans out in the first milliseconds of the throttle bore being opened. Then quickly rise for a spit second as the throttle closes and the mixture richens. The volt meter should stabilize at the original operating voltage when the engine returns to idle.

Formula Drift Malaysia 2009 ( Part 3 )

How Rotary Engines Work (Part 4)

Source by: http://auto.howstuffworks.com/rotary-engine3.htm

Rotary Engine Assembly
A rotary engine is assembled in layers. The two-rotor engine we took apart has five main layers that are held together by a ring of long bolts. Coolant flows through passageways surrounding all of the pieces.

The two end layers contain the seals and bearings for the output shaft. They also seal in the two sections of housing that contain the rotors. The inside surfaces of these pieces are very smooth, which helps the seals on the rotor do their job. An intake port is located on each of these end pieces.

One of the two end pieces of a two-rotor Wankel engine

The next layer in from the outside is the oval-shaped rotor housing, which contains the exhaust ports. This is the part of the housing that contains the rotor.

The part of the rotor housing that holds the rotors
(Note the exhaust port location.)

The center piece contains two intake ports, one for each rotor. It also separates the two rotors, so its outside surfaces are very smooth.


The center piece contains another intake port for each rotor.

In the center of each rotor is a large internal gear that rides around a smaller gear that is fixed to the housing of the engine. This is what determines the orbit of the rotor. The rotor also rides on the large circular lobe on the output shaft.

Next, we'll see how the engine actually makes power.