Newb question: On the 2013 base Fit (US, so it's the 1.5 I-VTEC), do the fuel injectors (how many are there?) fire all the time or is this a sequential injection system and the injector near an open intake valve opens whereas an injector near a cylinder with a closed valve doesn't bother opening? I understand that earlier multi-port systems were kinda primitive and just shot gas out no matter what, but I guess I'd be surprised if a new current car still did that.

Anyone know? Of course, once everything goes DI it'll be moot, but I don't have DI..

 

On modern EFI the injection is "sequential", that is the injection is carefully timed to occur just as the valve opens on the intake stroke. The older method was a vestige from the original EFI's built years ago when computers were a lot less powerful. In the beginning the injector pulses were triggered mechanically by a set of "points" in the bottom of the distributor. There were only two sets of points so half of the injectors were fired at a time. (2 in a four cylinder, 3 in a six, 4 in an eight). Those days are long gone as computers are far more sophisticated today.

Of course the next generation of Fit (2014?) will have Direct Injection where the fuel is shot right into the cylinder. More power, better mileage.

 

More frequent oil changes if they don't eliminate the tendency of DI engines to dilute the oil with fuel.





I'll take the DI, BTW.

 

Fuel in the oil of DI engines is a concern.....but only to some. It is not so common on all engines as some thing. Of course, if its your engine getting the fuel in the oil then to you it is a big problem. It appears to be worse with turbo engines than with non-turbo's. You can read about that to see why. Also, DI has a tendency to work better at high speeds more so at low. This may also explain why some owners see more of a problem than others, its based on how they operate the vehicle. Toyota has a system that is dual in that it uses more conventional injection at lower speeds and then switches to DI at higher speed. This improves drivability and may also reduce the oil dilution issue.
DI is nothing new. Last I read the first use of it was in 1902. It was used extensively in WW1 and continued in use after that but mostly in aircraft use. Seems aircraft get all the good stuff. Those WW1 fighters had beautiful double overhead cam, four valve engines long before your Honda was ever thought of. Nothing much new in this world....its a slow evolution of ideas.
I have no worries about DI in my next Fit. Meanwhile adjust those valves and tighten your spark plugs once in awhile...ask me why some time.