Every vehicle owner as well as technician should know the fuel pump priming sequence, since this is one of the key factors to make sure that the engine runs properly and starts with no problem. The priming sequence is a series of brief ignition cycles that prime the fuel system to ensure that the engine has adequate fuel as soon as it cranks up.
Ignition Initiation: The sequence initiates when the ignition key is moved from “off” to “on” but before you move into “start.” This operation turns on the fuel pump relay, which energizes the fuel pump.
Fuel pump activates for a short period right after turning the key, normally two to three seconds. This is the period in which the pump pushes fuel from the tank through the fuel lines towards the engine.
Higher-Up Time: For these crucial seconds, the pump has to get pressure applied as soon it starts running so that all fuel system is pressurized. Most vehicles require between 30 to 60 pounds per square inch (psi), the acceptable levels will depend on your vehicle's make and model. It is necessary to create the brought strain inside the combustion chamber, so as gasoline aerosolization.
The System will Check: All modern vehicles with ECU's are monitoring the pressure build-up. A system may not allow the engine to crank if it does attain pressure on time while some systems will let you crank but not provide spark until enough fuel pressures are present as damage could be done from bad fuel delivery.
Automatic Fuel Pump Shut-off: The fuel pump will shut off automatically after the ignition has been turned to "on" without a commencement to operate, avoiding over-pressurizing and potential damage to the fuel system. This security feature also helps in saving your battery.
Re-prime: should the engine not start immediately, turning the ignition off and then to the on position will re-engage the prining sequence giving another opportunity for the fuel pump to pressurize.
This is not only a necessary startup sequence but also often a diagnostic I tool. For example if there is a failure in the priming sequence, It means some issues like fuel pump fault, clogged low pressure filter or electrical connection problems. This can help make the primer run perfectly and in turn this extends the life of your fuel pump, helping prevent future failure which would hurt your vehicle performance.
Or in the words of Henry Ford: "The only real mistake is the one from which we learn nothing." Localizing and securing the fuel pump priming system will help car owners/high techs keep up fuel pump outside to carry out at play optimal module strategy fully of subnotch.
To get more of them and information about different types of fuel pumps,their operation tips visit Fuel Pump. This resource will give you an excellent understanding of how the fuel system works along with detailed guidance on troubleshooting common problems.