What is timed fuel injection? (2023)

What is timed fuel injection?

Injection timing is the timing of when fuel is injected into the cylinder, which alters when the combustion takes place. The time of when fuel is injected can be altered to be injected at different points in time.

It is important to understand that a fuel injector have a lag time, a dead time before it opens.

Injection timing is an important engine parameter, which significantly affects the odorous emissions. If injection starts earlier, the initial air temperature and pressure are lower so the ignition delay would increase.

This causes your engine to use more fuel to compensate for reduced power. Overheating: If the air and fuel mixture is ignited too soon in the combustion process, the heat generated will increase. This can damage different parts of the engine.

Engine timing refers to the pistons, valves, and spark plugs all doing their thing at precisely the right moment. In a four-stroke engine – the type used in all modern vehicles – each piston moves four times to complete one cycle.

One of the most noticeable problems caused by faulty fuel injection pumps is that your engine is not running smoothly. When the fuel is not entering your engine properly, then it affects the performance of your car. This may not be noticeable at times.

It can be found that with the delay of the fuel injection timing, the torque first increases and then decreases. The brake-specific fuel consumption decreases initially and then increases at maximum brake torque spark timing.

How do you adjust variable injection timing?

Adjustment of the Mechanical VIT - YouTube

Effects of retarding ignition timing:

Because of the spark retardation, the combustion of the mixture takes a longer time. Thus the pressure of combustion products rises after the piston starts to move away from TDC and because of increasing volume, the gases are not able to attain the peak pressure.

One of the major reasons for injector pump failure is an excessive buildup of deposits. There are two types of deposits – internal injector deposits and external injector deposits. External injector deposits are caused by fuel that's not wholly burned that often builds up around the injector holes.

How To Tell If Your Engine Timing Is Off - YouTube

Advancing the timing means that you are changing when the combustion process will take place in relation to the piston's position. By advancing the injection timing, the combustion process will take place before the manufacturer initially intended it to. Doing this should increase horsepower.

2-3 hp per degree is a good rule.

All discussion of ignition timing starts with the initial timing. This is the amount of advance at idle with the spark triggered Before Top Dead Center (BTDC). Most stock street engines call for 6 to 8 degrees of initial advance, but this is not set in stone.

Ideally, the time at which the mixture should be fully burnt is about 20 degrees ATDC. This will maximize the engine's power producing potential.

What Is Fuel Quality Setting (FQS) FQS is a manual adjustment of fuel injection timing. This setting is used when we get fuel of different ignition lag. One of the most important property is ignition lag.

ZERO SETTING means, the fuel plunger helix should be inline with the spill port so that there is no injection. This is ensured while assembling the rack in the sleeve of the plunger. One gear of the sleeve is slightly cut which should go in between the two cut gears of the rack, which ensures zero setting.

What is variable injection timing?

Variable injection timing, often referred to as VIT, is a term that describes the process of adjusting the timing of starting fuel injection. More specifically, it refers to the mechanism which either advances or retards fuel into the injection pump.

When any changes are made to the engine of a car, the ignition timing is adjusted accordingly. If not, you could experience several problems with your engine with improper ignition timing like knocking, hard to start, increase fuel usage, overheating, and reduced power.

There are three primary issues that a fuel injector will run into, which is becoming clogged, being dirty or they will leak. Other issues, such as computer errors or failing sensors, can cause the fuel injectors to act incorrectly, but these are not a result of failing injectors.

Ignition Timing: Result of Incorrect Timing and How to Check Yours

On a typical engine, the shop time quoted will be 10 to 12 hours. On an easy engine with a skilled mechanic, you may get quoted as little as 8 hours, while bigger jobs may require as many as 15 hours. The majority of quotes should fall in the first time frame.

Yes. In the case of both valve timing and distributer timing (in older cars with a spark distributer) changing the timing will affect the idle speed at the same throttle setting, because it will affect the efficiency of the engine at that throttle setting.

Pulling timing refers to a reduction/delay in the spark plug being ignited. Usually from low octane fuel, knock, running rich, boosted applications, etc. It reduces the power of the car and helps prevent detonation or harm to the engine.

Common causes of injector failure

While many things can cause breakdowns, the most likely cause of premature failure is fuel contamination. Fuel contamination occurs when debris in the fuel gets past the filtration, destroying the sealing surfaces.

Two ways to reduce or eliminate fuel pump failures:

Never let your fuel level get below 1/8th to 1/4th of a tank. Change your fuel filter at 30,000 mile intervals (most vehicles)

The engine surges while driving.

This is caused by too much fuel being sent to the engine. When that happens, you'll notice your engine surging—the vehicle will repeatedly pick up speed and then drop speed, even though you haven't touched the gas pedal or the brake.

Why is my engine knocking when I accelerate?

Engine knocking happens when some fuel in the cylinder detonates before the other fuel. During normal operation, the spark plug starts the combustion process and burns all fuel in the cylinder, thus controlling the explosion. Spontaneous ignition of fuel and air in the cylinders results in engine knocking.

An engine will begin to ping at a relatively rapid pace when the fuel grade gets too low in its octane rating. A pinging noise in the engine can also indicate the need to repair the part of the car that tells the coil when to fire the cylinder. You might have carbon build-up in the combustion chamber.

Increasing the fuel's octane level:

Engine knocking often occurs when the air-fuel mixture is incorrect. To counter this, you can add an octane booster in the mix. This can help ensure proper octane rating, which can then stop the knocking. The recommended minimum octane level in the US is 87.

The fuel pumps would need to be adjusted collectively, when the fuel combustion quality reduces. Hence if combustion was slower than normal, possibility due to a high level of Conradson Carbon or Ashalptenes, then the fuel timing could be advanced.

The needle shutdown of fuel injectors leads to an undesired fuel dribble that forms unburned hydrocarbons and decreases the engine thermal efficiency in modern engines. Understanding of the fuel dribbling process is of great importance to establish its minimization strategy for optimal use of conventional fuels.

An Injection Pump is the device that pumps fuel into the cylinders of a diesel engine. Traditionally, the injection pump was driven indirectly from the crankshaft by gears, chains or a toothed belt (often the timing belt) that also drives the camshaft.

Advancing timing will likely cause your coolant + oil temps to go up. If you are very worried about overheating/melting something consider water injection.

It can also be seen that advancing the timing increases the peak temperature (see Fig. 16.18) achieved during combustion, but tends to decrease the release temperature, while retarding reduces the peak temperature but increases the release temperature.

Lighter springs allow the advance to begin at a lower rpm. Heavier springs delay the onset and slow the rate of advance. A typical mechanical-advance curve might start advancing at 1,500 rpm and achieve full advance by 2,600 rpm.

What are three types of fuel injection systems?

Your vehicle can be equipped with one of the three most common injection systems on the market. GDI (Direct injection), SDI (Semi-direct injection) or TBI (Throttle body injection).

Yes, Fuel Injectors Can Improve Horsepower

The answer to the question, “Can new fuel injectors help improve horsepower?” is yes. At their peak, fuel injectors can add 10 extra horsepower to a vehicle. By creating a larger flow rate of air, fuel injectors can make a measurable, yet not massive difference.

Fuel injection is an engine technology. The engine supplies fuel directly to the cylinder in the manifold. The entire fuel injector system is controlled by an Electronic Control Unit. It is this unit that monitors engine temperature and oxygen levels. It also monitors the air intake and many other vital elements.

When any changes are made to the engine of a car, the ignition timing is adjusted accordingly. If not, you could experience several problems with your engine with improper ignition timing like knocking, hard to start, increase fuel usage, overheating, and reduced power.

How To Tell If Your Engine Timing Is Off - YouTube

One of the most noticeable problems caused by faulty fuel injection pumps is that your engine is not running smoothly. When the fuel is not entering your engine properly, then it affects the performance of your car. This may not be noticeable at times.

Direct injection

In the previously mentioned systems, the fuel is sprayed on the intake and there is always a potential of fuel condensation to some extent. However, in the DI system, all the fuel is directly injected into the cylinder which produces maximum fuel economy and this is its greatest advantage.

As technology advances, direct injection engines may become easier to manufacture, but, for now, sequential multi-port injection remains the most common fuel injection system in cars today. It provides the right mix of efficiency and affordability for most applications.

Port or multipoint fuel injection. Sequential fuel injection. Direct injection.

The better fuel efficiency is a big bonus too, but EFI can also offer slightly more power over carbureted systems, along with a faster throttle response. Finally, fuel injection systems are usually very reliable, and require little to no maintenance.

What makes more power carburetor or fuel injection?

Warren Johnson: Properly tuned, carburetors make more peak power than EFI in a Pro Stock engine. A carb's pressure differential atomizes the gas a lot better than spraying fuel through an orifice. But EFI has a broader powerband and superior cylinder-to-cylinder fuel distribution.

Best dirt bike for fuel economy: Honda CRF300L

The Honda CRF300L strikes the right balance of performance and economy with a claimed 75 miles per gallon.

Unstabilized gas in a motorcycle can start going bad in about 30 days, especially when it is not being used. The exposure to oxygen eventually changes the chemistry of gas which can lead to gum and varnish deposits. Gas should not be used if it has been sitting for longer than 6 months.

Unlike carburettors, fuel injectors don't take kindly to dust. Stay away from adulterated fuel and fill up at reputed company-owned outlets. Take care to ensure that the fuel level never dips below a certain limit. If the latter happens, the fuel pump may go kaput.