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I never understood why we need a fuel pump and a fuel injector .. and a valve that opens to let fuel in the cylinder.
by mrfusion 6y ago
I never understood why we need a fuel pump and a fuel injector .. and a valve that opens to let fuel in the cylinder.
- bagels 6y agoFuel isn't going to move if you don't have a pressure differential. Exhaust will go back in to the gas tank without a valve (injector). Need to control the amount of fuel on each combustion cycle. That's why.
- culopatin 6y agoTank is in the back. The injector only works properly at elevated fuel pressure otherwise it would just drip out. Like a shower head with no pressure, it would just dribble out. Valve lets in a mixture of air and fuel, not just fuel, and allows compression to happen. If that wasn’t the case you’d have to have a mixture injector that closes during compression and explosion. Without it, the explosion would expand in the intake runner instead of pushing down the piston.
- mrfusion 6y agoThanks. So does the injector get fuel on the back of the valve when it sprays?
- culopatin 6y agoUnless it’s direct injection, yes. It sits there for a little bit mixing up with the air. Also the hot valve vaporizes the fuel a bit more. In direct injected engines, the injector shoots on the piston.