My parents used to have a car without it and you would have to pump the gas a few times to get the car to start. With electronic injection, you dont have to do that. But is it possible that an engine with it could still flood? What if you have leaky injectors?

 

Yes. Especially with leaky injectors, which would also lead to fuel in the engine oil and so reduced service life of the engine.



If you go to start an injected engine and don't let it crank long enough so it just-doesn't-quite start, it can have an extra 'crank' worth of gas in the cylinders that will require some more cranking on the next attempt to clear.

 

Pumping before the start.. you are just moving the throttle plate around. There is no power going to the magnet that draws the pin out of the way to let fuel flow with the key off. After you are turning the key you can flood like Stocker said with a poorly timed key release. I have done that a few times with the genesis for some reason and will leave it a lone for a second before trying again. When it fires up you can tell its not happy about that at all. I have never had it not start and flood out, but letting go too soon = genesis pissed off when it fires up... or sounds it anyway. If the injectors are leaking then you are starting off with too much fuel in there just like pumping away on an older carbureted setup.

 

BTW, you can "clear" a flooded EFI car by holding the throttle wide open and then cranking the motor. This tells the ECU not to open the injectors. This is also useful when doing a compression test on an EFI car since fuel in the cylinder can damage your compression gauge.