In a fuel injection engine, the intake valves release air into the cylinder. The piston moves upward toward TDC, compressing the air, and the intake and exhaust valves close. … The expanded gases force the piston back down to BDC during the power stroke, moving the crankshaft each time.
How do I know if my injection timing is correct?
Turn the engine so that the unit to be checked is toward the TDC of compression stroke (plunger upstroke) so that hair line marking on plunger and pump body are coincided. When hair lines are coincided, stop turning and check the mark on the fly wheel whether timing is correct or not.
How do I set the timing on my injection?
There are several ways you can adjust injection timing, depending on the type of engine you have and how old it is. The most common ways to adjust injection timing are programming the ECM, adjusting the fuel injection pump, replacing the camshaft, and replacing the cam followers or gaskets.
How is fuel injection timed?
Injector commonly refers to the nozzle holder and nozzle assembly. Start of injection (SOI) or injection timing is the time at which injection of fuel into the combustion chamber begins. It is usually expressed in crank angle degrees (CAD) relative to TDC of the compression stroke.
Why is fuel injected before TDC?
Longer delays between injection and ignition lead to unacceptable rates of pressure rise (diesel knock) because too much fuel is ready to burn when combustion eventually occurs. … Advanced injection timing is expected to compensate for these effects. The engine has standard injection timing of 30° before TDC (BTDC).
How do you test an injection pump?
There is an easy do-it-yourself way to test your injectors & pump. 1- remove the injector from your engine. 2- hook the steel fuel line back up the the injector with the injector facing away from the engine. 4- turn the engine over and let the fuel spray out of the injector onto a piece of cardboard.
How do you adjust the timing on a fuel pump?
Adjustment of Fuel Pump Timing
- By adding or reduction shims on the pump base, or.
- By turning the plunger up and down adjustment screw on the pump roller guide, or.
- By shifting the coupling flange between the pump and the drive side of the engine in case of combined unit system, (for small engine)
What is variable injection timing?
The Variable Injection Timing (VIT) function of a marine diesel engine comes into play during load dependent adjustment of the combustion pressure. … By controlling the injection timing of the fuel in the fuel delivery pump and advancing the fuel pump injection timing, VIT increases the maximum pressure in the engine.
Does advancing timing increase horsepower?
The major benefit to advancing the timing of a vehicle’s ignition is increasing the horsepower of an engine. Advancing the ignition timing helps raise the high-end power while reducing the low end. It also helps get the spark past the ignition delay and run at peak power.
How do you set the injection pump timing on a 6.5 Diesel?
The timing values will fluctuate, set to an average of 3.5 degrees. Turn the engine off before loosening the pump flange nuts to adjust the timing. If the engine stalls during the procedure rotate the injection pump 1mm towards the driver’s side of the vehicle to advance the timing.
What are the two basic types of fuel injection systems?
There are two basic types of fuel injection systems used on passenger cars and light trucks, multiport fuel injection and throttle body fuel injection.
What are three types of fuel injection systems?
The three major types of fuel injection are known as throttle body injection, multiport injection, and direct injection.
How fast do fuel injectors work?
The process of diesel injectors opening, closing and dispensing the correct amount of fuel happens in milliseconds. Injector cycle firing is on average completed in 1.5 to 5 milliseconds. Diesel fuel injectors come in different shapes and sizes depending on the engine make and model as well as power demand.
What are the benefits of injection timing?
The injection timing is a very important parameter to ensure better combustion, and this depends on valve timing and ignition timing; those are main factors to optimize the heat release which has effects on the performance of the engine . In this CNGDI engine the fuel injection pressure is 20 bar.
How do the injection timing and fuel quality affect the engine knock?
The results show that as for Position A (ethanol injecting toward spark plug), with the delay of injection timing, knock tendency and its intensity increase initially and then decrease due to the comprehensive effect of ethanol evaporation and fuel stratification; on the contrary, for Position B (ethanol injecting …
What is the purpose of injection timing?
Injection timing, also called spill timing, is the moment when diesel fuel enters the cylinder during the combustion phase. When you adjust the timing, you can alter when the engine injects the fuel, therefore changing when combustion occurs.