Loop the Loop

The engine computer already has built in data to deal with engine start and warm up along with running around. This mode is known as open loop. The stored information is similar to the read only memory that tells the Space Invaders always begin their video attack with plenty of aliens – and always find more where they came from. Once the engine and oxygen sensor reach operating temperature the system moves into a closed loop. The oxygen sensor makes like Sputnik in the exhaust pipe, and broadcasts a signal as voltage to the engine computer. In the ideal world of complete combustion, the fuel to air ratio hovers at the point where the most complete burn of the fuel added to the air is reached. This 14.7 parts air to one part fuel ratio is known as stoichiometric. If an oxygen sensor goes wonky it can send the wrong signal. Too much fuel and the engine runs rich. Too little fuel and the engine runs lean.

Oxygen Sensor Check Remove and Replace

Useful Things:

• Engine Code Reader or Multimeter
• Hand Tools
• Oxygen Sensor Socket

Remove and Replace

Fuel economy can suffer if an engine is running too rich. An engine that is running lean can run down on performance and experience internal damage. A foul running engine can also ruin the catalytic converter, a far more expensive part than an oxygen sensor. The same engine computer that makes things run right also knows when things have gone wrong. A malfunctioning O2 sensor is one of numerous faults that can trip the Check Engine Light or throw a malfunction code. While every vehicle made after 1996 adheres to a standard known as On Board Diagnostics II (OBD-II), cars and trucks made before 1996 are not so standardized. Adding to the confusion is that some automobiles can have four or more (!) O2 sensors. Removing and replacing a bad oxygen sensor is a matter of lefty loosey and righty tighty. Removing and replacing a good oxygen sensor is not going to solve any problems. A code reader or voltage multimeter can help sniff out the bad ones.

Related: Tool of the Week: Engine Code Reader

More: Checking ECU Engine Codes on StarQuestClub

When cars used carburetors, the fuel pump was usually a mechanical deal bolted up to the side of the engine. Carburetors are now about as common as console black and white console televisions with built in hi-fi phonograph and stereophonic sound. Fuel injection is the fuel delivery standard. A modern fuel pump is capable of maintaining the pressure and flow required by the electronic fuel injection system, itself powered by electricity created by the alternator. If the fuel pump quits? Game over.

Step-by-Step Gallery with E-Z Captions

Electric Motor

The fuel pump more or less an electric motor. The motor turns rollers or turbine vanes inside the fuel pump. The pump takes fuel from the tank, pressurizes it, and delivers it down the fuel lines into the engine. Fuel  pressure to the engine is controlled by a fuel pressure regulator. The fuel pump keeps spinning regardless of what the engine demand is up to. Divorcing the fuel pump from the engine has spawned all manner of fuel delivery arrangements. There are inline single fuel pumps, single in tank pumps, and even a combination of in tank and inline. Consulting the service manual is the first step before attempting to service a fuel pump.

Symptoms of a tired or waning fuel pump include excessive whining, hard engine starting, or bucking and loss of power under full throttle conditions. Before replacing pump, first be sure that filters, fuel pickups, fuel pump relays, and electrical connectors are in good working order. A clogged fuel filter can restrict fuel flow and cause some of the same symptoms as a dead or dying fuel pump. Finally, exercise the utmost in caution if working with gasoline. Do not work near gas wall heaters or water heaters. Pilot lights can ignite fumes! Use safety glasses, gloves, fuel-approved containers. And yes – have a fire extinguisher nearby.

Working on any car sometimes involves getting safely underneath to spin wrenches, or swing hammers. A floor jack and jack stands are the right tools for the job when it comes time to working on an automobile with more than one of its wheels removed. Choosing the right floor jack and jack stand set depends on the weight of your automobile. There’s no need to get a 12-ton set if you drive a 1982 Toyota Starlet. Conversely, an economy stamped steel 1-ton set won’t hold up a full-size pickup or SUV. Ground clearance, or lack of it, is another factor. Low-profile floor jacks will squeeze under most stock body cladding. A set of ramps are the answer for getting the floor jack under super low rides.

Step-by-Step Gallery with Bonus Captions

Key Points

Jacking and jack stand support points are crucial to safety. A jack or jack stand in the wrong location can cause vehicular or bodily damage! Your owner’s or service manual is a good place to find the right jack locations and jackstand points for your vehicle. Never jack up a vehicle from a point not designed to handle the load. If unsure about where to place a jack or jack stand, the best strategy is to stop. Do not attempt to guess at a good location. Putting holes in the floorboards or yourself is not the goal.

Back Down

When lowering the vehicle onto the stands or back onto the ground it is important to slowly release the hydraulic pressure inside the jack. Double check jack stand locations before lowering the car. If working with others yell “clear” or “potrzebie” before turning the handle on the jack. Slow lowering of the vehicle not only helps prevent damage, but allows time to see any potential hazards before they occur. Practice raising and lowering the jack to get a good feel for how it works before balancing 3000 pounds of car on it.

Of all the fluids contained in an automobile, oil is absolutely crucial to the survival of your engine. A thin layer of oil molecules rides between moving internal engine parts. These molecules prevent heat-producing friction from destroying your engine in short order. Keeping an eye on your engine oil level is as important as it is simple. Read on to see how.

How to check your oil begins with an understanding of the oiling system. Bolted to the underside of the engine is an oil pan. At the bottom of the oil pan there is a pickup for the oil pump. The pump circulates oil from the bottom of the pan and through the engine. Any loss of oil pressure is instant bad news for the engine.

Every vehicle has a dipstick for checking oil that lives up to its name and dips into the oil pan itself. On the bottom of the dipstick are two marks. The upper mark indicates full. The lower mark indicates add. Since the dipstick only reads how much oil is in the pan itself there are a few rules to follow when checking your oil.

The first rule is that you check the oil while the vehicle is on level ground. The oil dipstick extends down into the engine oil pan, so it cannot give a correct reading if the oil is gathered at the back, front, or side of the pan. The second rule is to wait long enough for oil to drain back into the pan before checking. A couple of minutes should be enough.

The ongoing argument is whether to check your oil when the engine is hot, or when the engine is cold. The cold crowd will argue that when the engine is cold and at rest, all the oil is in the pan, and therefore the dipstick will tell the truth. The hot crowd will argue that oil expands when hot, so the best time to check the oil is when the engine is warm.

Both crowds are right. As long as the first two rules are adhered to everything should be fine. If your driveway at home is nice and flat then check your oil in the morning. If you live and park on a steep hill then check your oil at the gas station when the engine is warm. Hot or cold, every other fill-up is a good schedule for oil checks.

Lastly, there is the reading of the dipstick itself. As a general rule, add one quart of only if the dipstick reads below the add mark. Consult your owners or service manual for motor oil type and viscosity. Pour oil only where it belongs. Engine oil filler caps are usually labeled with the word OIL and often include a pictogram of what looks like Aladdin’s lamp. Find the lamp under the hood before the one on the dash lights up.

Park the car on level ground, and set the emergency brake. Open and prop up the hood, then locate the oil dipstick. Pinch a rag around the dipstick as you draw it out of the engine to remove and catch any oil.

Reinsert the clean dipstick into the engine until the handle is fully seated in the dipstick tube.

Draw the dipstick back out and hold level to take a reading. The upper mark means full. The lower mark means add. Here the oil level is low.

To add engine oil, find and remove the oil filler cap. Placing the cap in the rag keeps oil off the engine and the exhaust manifold.

Add one quart of oil only if oil level is below add mark on the dipstick. A funnel makes adding easy.

Check the oil again after a minute to let it settle down into the pan. Good? Replace and tighten oil filler cap.