General Maintenance Tips For Your Car

A well maintained vehicle will never let down its owner. It will not desert you when you need it most. Here are a few maintenance tips for your car

Check the Engine Oil: To prevent the engine from deterioration, its important that the engine maintains the amount of oil it is programmed to receive. Negligence in doing so will lead to a deteriorating engine performance, meaning you'll get falling mileage.

Make Sure the Lights are working properly: It is important for the lights to be properly focused, for your own and for the oncoming vehicle's safety. Travel on low beam so that it does not obstruct your view instead of helping you along.

Have Suitable Tyre Pressure: The required amount of air pressure needs to be strictly maintained if your car is to get the right mileage and pick-up. Make sure pressure is not to high or you'll shorten the life of your tyres.

Radiator Water: If your engine uses water for cooling, take care to ensure that it is regularly changed.

Some other tips...
Get your vehicle serviced only at authorized service stations
Check the engine oil level once every two weeks. Also check the levels of coolant and water in the radiator and battery.
Always use genuine spare parts.
Avoid accelerating and braking abruptly.
Shut up the engine whenever you expect to wait.
Drive at a moderate speed of 45-55 km/h to maximize fuel efficiency.
Use air-conditioning only when necessary.
Avoid riding on the clutch pedal, and release the clutch pedal fully while driving.
Maintain optimum air pressure in your tyre to improve mileage.

Potential causes Dieseling

An automobile engine that is dieseling will typically sputter then gradually stop rather than continue running as if the engine was not switched off at all — the latter would usually indicate an electrical fault.


Potential causes

This condition can occur for a multitude of reasons:

* Built-up carbon in the ignition chamber can glow red after the engine is off, providing a mechanism for sparking unburnt fuel. Such a thing can happen when the engine runs very rich, depositing unspent fuel and particles on the pistons and valves. Similarly, non-smooth metal regions within the piston chamber can cause this same problem, since they can glow red. It has also been suggested that an improperly rated sparkplug can retain heat and cause the same problem.

* A carburetor that does not close entirely can contribute to running once the engine is off, since the extra fuel and oxygen mixture can combust easily in the warm piston chamber. Similarly, hot vaporized oil gases from the engine crankcase can provide ample fuel for dieseling.

* Incorrect timing.

* An engine that runs too hot or too lean may produce an environment conducive to allowing unspent fuel to combust.

* An idle speed that is too fast can leave the engine with too much angular momentum upon shutdown, raising the chances that the engine can turnover and combust more fuel and lock itself into a cycle of continuous running.


Potential fixes

Items similar to carburetor cleaners and carbon cleaners have been suggested as partial remedies for attempting to clean the piston chambers and valves of engines that run too rich.

For those engines that have sharp metallic edges, it has been noted that poorly milled heads and blocks can contribute to this problem, so having the rough spots smoothed may help.

For those engines that run too hot or too lean, verify that all mechanisms in place to cool the engine properly function as they should. Replace the thermostat if necessary. Clean the radiator. Verify that all auxiliary fans engage at their proper temperatures, and ensure that the thermostatic sensors on belt driven fans engage as necessary.

In the case that there is too much angular momentum, lower the idle speed if possible.

Changing the Fuel Filter

A vehicles fuel filter is used to keep the fuel that is used in the fuel injection system clean to avoid plugging fuel injectors and fuel pressure regulator. The fuel filter should be changed between 25,000 and 35,000 miles depending on driving conditions. First locate and identify the fuel filter, all vehicles are different so you might have to look around for it. Some are under the hood and others are under the car or truck like the one used in this example.

If you are unsure were your fuel filter is located then you can buy an online schematic at Mitchell1 Online. (Wear protective gloves and eyewear when replacing).

Locate and replace the fuel filter
Remove the fuel filter connection

Remove fuel filter connections from fuel lines. A small amount of fuel will leak out when connections are removed. Next remove the fuel filter mounting bracket bolt and remove filter.

Install fuel filter mount

Remove fuel filter mount from old fuel filter and install it on the new fuel filter. Make sure that the direction arrow is pointing in the direction of the engine. (forward in most cases)

Install new fuel filter

After the fuel filter mount is installed reinstall fuel filter. Make sure the sealing "O" rings are in place, in good condition and free from debris. Remount filter and reconnect. Start vehicle to check for leaks

Detonation, Knock, and Pre-Ignition 101

As you probably have already figured out, detonation (aka "knock") is a big issue in the world of forced induction. You probably know that detonation is a bad thing, and that by adding a supercharger (or any forced induction power adder), you must take additional measures to avoid detonation, especially if your engine has other modifications. Normally the simple solution to stop detonation is to run higher octane fuel... but before we get ahead of ourselves, let's start from the beginning.

What is detonation / knock?

Under normal conditions, the combusting air and fuel mixture inside the combustion chamber ignites in a controlled manner. The mixture is ignited by the spark, normally in the center of the cylinder, and a flame front moves from the spark towards the outside of the cylinder in a contolled burn. Detonation occurs when air and fuel that is ahead of the flame front ignites before the flame front arrives because it becomes overheated. Under these conditions, the combustion becomes uncontrolled and sporadic and often produces a pinging noise, or a "knock" noise when the conditions become worse.

So far, detonation sounds cool... why is it bad?

Detonation is definitely not cool. Detonation causes sudden pressure changes in the cylinder, and extreme temperature spikes that can be very damaging on engine pistons, rings, rods, gaskets, bearings, and even the cylinder heads. Even the best engine components cannot withstand severe detonation for more than a few seconds at a time. More severe detonation obviously leads to more severe forms of engine damage. If there is enough heat and pressure in the combustion chamber, detonation can begin to occur before the spark plug even fires, which would normally initiate the combustion. Under these circumstances, known as "pre-ignition", the piston may be travelling up towards a wave of compressed, exploding gas. These are the worst kinds of detonation conditions, and can bend con-rods and destroy pistons.

What causes detonation?

Detonation occurs when several conditions / factors inside the combustion chamber exist at the same time. Increased compression, high temperatures, lean fuel/air mixture, advanced ignition timing, and lower octane fuels are all factors that PROMOTE detonation conditions. The good news is that, because there are so many factors in play, you can always find a way to eliminate detonation if it exists.

So, where do superchargers fit in?

A supercharger increases the amount of air inside the combustion chamber, which in turn increases the compression inside the combustion chamber. Along with increased compression comes higher temperatures and higher pressures, which as we know, tend to increase the chances that some form of detonation will occur. In order to compensate for the increased compression and heat, we must change one or more of the other factors / conditions to move us away from our detonation threshhold. Tuning the supercharger system to the engine in this way for maximum performance without detonation is something that supercharger manufactuers do so, chances are, you won't have to worry about it unless you do other modifications to your engine that place you closer to your detonation threshhold.

How do I get rid of it?

The two most common tricks used by supercharger manufactuers and engine tuners looking to obtain maximum performance without detonation is 1. use higher octane fuel, and 2. retard the ignition timing.

Higher octane fuel burns more controllably and is not as likely to combust before the flame front. This is why racing engines use 100+ octane gasoline. The ONLY benefit of racing gasoline is that it moves you away from the detonation threshhold, which allows you to be more aggressive with power producing factors - i.e. raise compression, advance timing, etc. This is why you'll be disappointed if you put racing gasoline in your mom's bone-stock '82 Toyota Cressida thinking you'll turn it into a race car. If you don't have detonation, the increased octane will do you no good. For cars designed for daily street driving, you obviously won't want to fill up with 100+ octane fuel every week at the tune of 5 bucks a gallon. This is why supercharger manufactuers tune their supercharger systems to run properly without detonation on 91 octane fuel - aka "premium" at your local gas station (in some states premium gasoline is around 93 octane).

Retarding the ignition timing will delay the timing of the spark, which also moves you away from your detonation threshhold. Most popular "power programmers" or "chips" increase engine power by advancing the ignition timing, and requiring you to run a higher octane fuel to avoid detonation. These work great, except the advanced ignition timing is NOT compatible with most superchargers, unless you're happy to run 100 octane fuel. In fact, many supercharger systems include an "ignition boost retard" that retards the ignition timing when it senses boost from the supercharger. This allows you to maintain stock performance while not under boost, yet still remain safe while the supercharger is making its boost (and power).

Another way to avoid detonation is to cool the incoming air charge to lower the temperature inside the combustion chamber. On a supercharged application, this task can be handled by an intercooler or by a water injection system (less common). The intercooler takes the incoming air charge and passes it over a series of air-cooled or water-cooled fins and ducts, thus cooling the air in the same way that a radiator cools your engine's coolant. Intercoolers are thus very popular in higher output supercharger systems, where detonation becomes more of a problem. Often times, the intercooler allows you to run more boost and also allows you to eliminate the ignition boost retard, meaning you'll notice increased performance, and still experience no detonation. Another way to lower the temperature of the combusting air and fuel is to run cooler heat range spark plugs. Many supercharger manufacturers will recommend cooler plugs for you supercharged engine.

Because lean condition (fuel starvation) also contributes to detonation, it is important to make sure that the fuel system (pump, injectors, etc.) is capable of delivering the increased fuel requirements of the supercharged engine. Often times, an otherwise perfectly tuned engine will experience detonation just because the fuel pump can't deliver enough fuel to the engine. Upgrading certain fuel components is almost always necessary when supercharging an engine. Most supercharger systems normally include the upgraded fuel components if they are necessary. If you are installing a supercharger on an engine with other modifications, make sure you consider the additional fuel requirements and compensate with larger injectors and / or a bigger fuel pump.

Some modern vehicles come with "knock sensors" that listen for detonation, and automatically retard the ignition timing to eliminate detonation. Although these devices are effective in preventing engine damage, they are not tuned for performance, so you should not rely on the knock sensors and expect your engine to run its best.

Conclusion

Altough detonation can be potentially damaging to an engine, a simple understanding of what it is, and what causes it, will help you stay away from your detonation threshhold. Pay attention to "knock" and pinging noises that come from your engine becuase they could indicate detonation inside the combustion chamber and should be dealt with immediately. If you're looking for a new supercharger system, don't worry too much about detonation - the manufacturers have designed the system for use on your stock engine, and if you follow the manufactuer's fuel recommendations, you will not have a detonation problem. If you ever do notice detonation, perhaps from bad (low octane) gasoline or extremely high air temperatures, just drive with a light foot until you are able to resolve the cause of the problem.

Dieseling...Curing The After Running.

AFTER one, or both, of two things, causes RUN OR DIESELING: too hot and too fast. Something's hot, too hot, inside a combustion chamber(s) causing it to ignite by itself. Usually it's because of too lean a condition, sometimes at idle. Try richening the idle mixture screws (counter clockwise) a tad and setting the timing to specs. Also lower the idle speed a little. Having the throttle closed more helps it kill easier.

It could also be just the opposite, too rich a mixture has caused carbon build up in the chambers, and a hot piece of carbon in a combustion chamber is the ignition source. In that case, lean it out, lower the idle a tad, and put a can of good carbon cleaner in the gas tank, such as GM's Carbon-X, or Chevron's Techron. Even though the can of "stuff" says you can pour it down the carburetor, it's better to let it burn off slowly. Even if your neighbor says to pour water down the carb, don't. Cold water (or chemicals) makes valve stems look like pretzels, and the steam washes the oil off the rings, not a good thing to do. And then there's always the possibility of causing a chuck of carbon breaking off and getting stuck where it does lots of damage.

Next fill gas tank with premium fuel, use name brand gas, not independents where you don't know what you're getting. Don't use gasohol or gasoline with high alcohol content.

If after doing the above, it's still a problem, add an idle solenoid. It's powered by ignition electrics. When you shut off the ignition, the throttle closes more, killing it. Lots of Jeepsters had them but since people didn't understand how they work they tossed them.

To adjust the solenoid, disconnect the wire to it, adjust for the slowest idle possible, but do not let the throttle plates close all the way (this prevents them from wearing the ventures.) Connect the wire; adjust the position of the solenoid or the plunger for best curb idle with the plunger extended. If you no longer have the solenoid or bracket, visit a junkyard. Lots of 60's and 70's cars used them; likely donors are GM's.

Sometimes a dieseling condition actually makes the engine run backwards a moment, pumping oil OUT of things, not good. I've seen where people walked away from their cars letting it "run on." When they got back it had melted internal parts.

What causes dieseling

The most common cause of that is the failure of the anti dieseling mechanism, sometimes an "anti dieseling solenoid", found on most late model carbureted cars. What is happening is that the throttle is remaining partially open when the engine is shut down, which gives the hot engine sufficient fuel to run without a spark from the spark plugs. Most hot engines have sufficient carbon build-up that remains glowing red hot and acts as an igniter for the fuel. The solution is to make sure that the throttle closes completely when you turn off the ignition switch. Check the throttle stop and make sure that the fast idle on the choke or the "bottom stop" isn't what is stopping the throttle from closing. It must be the anti-dieseling mechanism and that mechanism must be functional.

Some motors (Olds for example in 85) used an actual servo motor for this function. The motor drives a worm gear which advances or retracts the idle speed control rod depending on what the computer tells it to do. When it is in the "closed throttle" position and the key is killed it retracts completely to allow the throttle plate to close completely thus preventing the "dieseling" that so many cars are experiencing.

What to do when engine problem

First try and detect the problem, is the car not starting, running roughly, conking out, or using too much petrol?

when the problem is found, isolate the system most likely to be its cause. If it is conking out, the fuel system may be at fault. If it is not starting, the electrical system may be worth looking at first. If the car is overheating, check the cooling system.

After you have isolated the most likely system, locate the weakest link in that system. The fuel pump, for example, is often the most vulnerable part of the fuel system.

Check each successive part in the system until the problem is solved.

Get the broken part replaced or repaired. Consult your car's manual for other specific problems you might be facing. This will help to speed up diagnosis, or you could send your car to the mechanics

Vapour lock

Vapor lock is a problem that mostly affects gasoline-fueled internal combustion engines. It occurs when the liquid fuel changes state from liquid to vapor while still in the fuel delivery system. This disrupts the operation of the fuel pump, causing loss of feed pressure to the carburetor or fuel injection system, resulting in transient loss of power or complete stalling. Restarting the engine from this state may be difficult. The fuel can vaporize due to being heated by the engine, by the local climate or due to a lower boiling point at high altitude. In regions where higher volatility fuels are used during the winter to improve the starting of the engine, the use of "winter" fuels during the summer can cause vapor lock to occur more readily.


Causes and Incidence

Vapor lock was far more common in older petrol fuel systems incorporating a low-pressure mechanical fuel pump driven by the engine, located in the engine compartment and feeding a carburetor. Such pumps were typically located higher than the fuel tank, were directly heated by the engine and fed fuel directly to the float tank inside the carburetor. Fuel was drawn under negative pressure from the feed line, increasing the risk of a vapor lock developing between the tank and pump. A vapor lock being drawn into the fuel pump could disrupt the fuel pressure long enough for the float chamber in the carburetor to partially or completely drain, causing fuel starvation in the engine. Even temporary disruption of fuel supply into the float chamber is not ideal; most carburetors are designed to run at a fixed level of petrol in the float chamber and reducing the level will reduce the air:fuel mixture delivered.

Carburetor units may not effectively deal with fuel vapor being delivered to the float chamber. Most designs incorporate a pressure balance duct linking the top of the float chamber with either the intake to the carburetor or the outside air. Even if the pump can handle vapor locks effectively, fuel vapor entering the float chamber has to be vented. If this is done via the intake system, the mixture is, in-effect, enriched, creating a mixture control and pollution issue. If it is done by venting to the outside, the result is direct hydrocarbon pollution and an effective loss of fuel efficiency and possibly a petrol odor problem. For this reason, some fuel delivery systems allow fuel vapor to be returned to the fuel tank to be condensed back to the liquid phase. This is usually implemented by removing fuel vapor from the fuel line near the engine rather than from the float chamber. Such a system may also divert excess fuel pressure from the pump back to the tank.

Most modern engines are equipped with fuel injection, and have a high pressure electric fuel pump in the fuel tank. Moving the fuel pump to the interior of the tank helps prevent vapor lock, since the entire fuel delivery system is under high pressure and the fuel pump runs cooler than if it is located in the engine compartment. This is the primary reason that vapor lock is rare in modern fuel systems. For the same reason, some carbureted engines are retrofitted with an electric fuel pump near the fuel tank.

Other solutions to vapor lock are rerouting of the fuel lines away from heat generating components, installation of a fuel cooler or cool can, shielding of heat generating components near fuel lines, and insulation of fuel lines.

A vapor lock is more likely to develop when the vehicle is in traffic because the under-hood temperature tends to rise. A vapor lock can also develop when the engine is stopped while hot and the vehicle is parked for a short period. The fuel in the line near the engine does not move and can thus heat up sufficiently to form a vapor lock. The problem is more likely in hot weather or high altitude in either case.


Incidence with other fuels

The higher the volatility of the fuel, the more likely it is that vapor lock will occur. Historically, gasoline (petrol) was a more volatile distillate than today and was more prone to vapor lock. Conversely, fuel for diesel engines is far less volatile than petrol and thus these engines hardly ever suffer from vapor lock. However, diesel engine fuel systems are far more susceptible to air locks in their fuel lines as standard diesel fuel injection pumps rely on the fuel being non-compressible. Air locks are caused by air leaking into the fuel delivery line or from the tank rather than the fuel evaporating in them. Eliminating such air locks requires an extended period of turning over the engine using the starter motor or manually bleeding the system.

Engine knocking

Knocking (also called pinking or pinging)— colloquially detonation—in internal combustion engines occurs when air/fuel mixture in the cylinder has been ignited by the spark plug and the smooth burning is interrupted by the unburned mixture in the combustion chamber exploding before the flame front can reach it. The engineered combusting process ceases, because of the explosion, before the optimum moment for the four-stroke cycle. The resulting shockwave reverberates in the combustion chamber, creating a characteristic metallic "pinging" sound, and pressures increase catastrophically.



Normal combustion

Under ideal conditions the common piston internal combustion engine burns its fuel air mix in the cylinder in an orderly and controlled fashion. The combustion is started by the spark plug some 15–40 crankshaft degrees prior to TDC (top dead center) the point of maximum compression. This ignition advance allows time for the combustion process to develop peak pressure at the ideal time for maximum recovery of work from the expanding gases. This point is typically 14–18 crankshaft degrees ATDC (after top dead center).

The spark plug produces an electrical spark that jumps a small gap from its center electrode to its ground electrode. This spark, if the air/fuel mix is within the flammable range for the fuel, initiates combustion. The initial phase forms a small kernel of flame approximately the size of the spark plug gap. For the first few milliseconds of the combustion process, this flame kernel is struggling to survive, producing only slightly more heat than is necessary to continue the combustion process. As it grows in size its heat output increases allowing it to grow even faster.

After this early slow burn phase passes, the flame kernel grows much faster expanding rapidly across the combustion chamber. This growth is due to the travel of the flame front through the combustible fuel air mix itself and due to turbulence rapidly stretching the burning zone into a complex of fingers of burning fuel air that have a much greater surface area than a simple spherical ball of flame would have. This greatly accelerates the combustion process.

In normal combustion, this flame front moves throughout the fuel air mix at a rate characteristic for the fuel-air mixture. Pressure rises smoothly to a peak, burning nearly all the available fuel then falls as the piston decends. In normal combustion this produces a rapid increase in cylinder pressure as the piston passes TDC and begins to move down the cylinder. As mentioned above in a properly tuned engine the maximum cylinder pressure is achieved a few crankshaft degrees after the piston passes TDC, so that the increasing pressure can give the piston a hard push when its speed and mechanical advantage on the crank shaft gives the best recovery of force from the expanding gases.


Detonation

The fuel/air mixture is normally ignited slightly before the point of maximum compression to allow a small time for the flame-front of the burning fuel to expand throughout the mixture so that maximum pressure occurs at the optimum point. The flame-front moves at roughly 33.5 m/second (110 feet/second) during normal combustion[citation needed]. It is only when the remaining unburned mixture is heated and pressurized by the advancing flame front for a certain length of time that the detonation occurs. It is caused by an instantaneous ignition of the remaining fuel/air mixture in the form of an explosion. The cylinder pressure rises dramatically beyond its design limits and if allowed to persist detonation will damage or destroy engine parts.

Detonation can be prevented by:

* The use of a fuel with higher octane rating

* The addition of octane-increasing "lead", methylcyclopentadienyl manganese tricarbonyl (MMT), isooctane, or other antiknock agents.

* Increasing the amount of fuel injected/inducted (resulting in lower Air to Fuel Ratio)

* Reduction of cylinder pressure by increasing the engine revolutions (lower gear), decreasing the manifold pressure (throttle opening) or reducing the load on the engine, or any combination.

* Reduction of charge (in-cylinder) temperatures (such as through cooling, water injection or compression ratio reduction).

* Retardation of spark plug ignition.

* Improved combustion chamber design that concentrates mixture near the spark plug and generates high turbulence to promote fast even burning.

* Use of a spark plug of colder heat range in cases where the spark plug insulator has become a source of pre-ignition leading to detonation.

Correct ignition timing is essential for optimum engine performance and fuel efficiency. Modern automotive and small-boat engines have sensors that can detect knock and retard (delay) the ignition (spark plug firing) to prevent it, allowing engines to safely use petrol of below-design octane rating, with the consequence of reduced power and efficiency.

A knock sensor consists of a small piezoelectric microphone, on the engine block, connected to the engine's ECU. Spectral analysis is used to detect the trademark frequency produced by detonation at various RPM. When detonation is detected the ignition timing is retarded, reducing the knocking and protecting the engine. See also Automatic Performance Control (APC).


Pre-ignition

Pre-ignition is a different phenomenon from detonation, explained above, and occurs when the air/fuel mixture in the cylinder (or even just entering the cylinder) ignites before the spark plug fires. Pre-ignition is caused by an ignition source other than the spark. Heat or hot spots can buildup in engine intake or cylinder components due to improper design, for example, spark plugs with heat range too hot for the conditions, or due to carbon deposits in the combustion chamber. Spark plugs with a high heat range will run hot enough to burn off deposits that lead to plug fouling in a worn engine, but the electrode of the plug itself can occasionally heat soak, and begin glowing hot enough to become an uncontrolled ignition source on its own. Bits of carbon that build up in a combustion chamber can also heat soak to the point where they also are glowing hot and ignite the air-fuel mixture before the proper time.

Pre-ignition and "dieseling" or "run on" are the same phenomenon, except in the latter case the engine continues to run after the ignition is shut off with a hot spot as an ignition source. Pre-ignition might cause rough running due to the advanced and erratic effective igniton timing and may cause noise if it leads to detonation. It may also cause "rumble" which is fast and premature but not detonating combustion.

This heat buildup can only be prevented by eliminating the overheating (through redesign or cleaning) or the compression effects (by reducing the load on the engine or temperature of intake air). As such, if pre-ignition is allowed to continue for any length of time, power output and fuel economy is reduced and engine damage may result. The engine might be slightly harder to get running at once after pre-ignition.

Pre-ignition may lead to detonation and detonation may lead to pre-ignition or either may exist separately.

diesel engine wet stacking

Wet stacking is a condition in diesel engines in which all the fuel is not burned and passes on into the exhaust side of the turbocharger and on into the exhaust system.

In generator sets, it is usually because the diesel is running at only a small percentage of its capacity. The accreditation body for hospitals JCAHO has been very concerned about this and has over the past few years dinged numerous hospitals for not running generator sets under at least 30% load as specified by the nameplate, or 50% of the normally connected emergency load, whichever is greater.

Some hospitals purchased large generators when they had the chance, anticipating expansion of the facility. As a result, some facilities fail to meet the percentage limits. Some of those that don't meet the load requirements have connected load banks to load up the generator to 80% of nameplate for a 4 hour annual run.

Wet stacking is detectable when there is a black ooze around exhaust pipe connections and around the turbocharger. Continuous black exhaust from the stack when under a constant load is also an indication that all the fuel is not being burned. Good preventive maintenance is critical for this type of generator application. There should be no surprises in the dark of night if the maintenance is being done correctly.

NFPA 110 speaks to the generator and wet stacking issues, and the 1997 JCAHO environment of care standards also address some change in the thinking on load bank testing.

A caution on load banks. If you choose to connect an external load bank to a required emergency power system, make sure that there is some automatic disconnect included that will take the load bank off-line if the generator is needed by the facility during the load bank run. If not, you may seriously overload the system if the emergency load from the hospital is added to the 80% load of the bank, causing a failure of the system when it is needed most.