80's EFI technolagy!

[ratvespa]

ok, I was a loafing around reading my kawi repair manual for my soon to be running 82 GPz1100 with efi (now with 100% more wiesco big bore goodness!).

So anyway, I was checking out the wiring diagram for the EFI, noticed that the all 4 of the injectors had one common power, and one common ground. Unlike most all EFI I have delt with, one common ground, then each injector has it's own power wire, so they can open up individually. So, question is, do all the injectors fire at the same time? I cannon imagine that being to efficient. Did any cars do this or was this a 80's bike thing?

If thats the case, I wonder how much more power and efficiency I could get out of going megasquirt (or microsquirt). I think I'll get it running with the factory set up, mabey do the break in on the pistons, then start tinkering with the 'squirt.

[KZQuixote]

Hi RatVespa,

Yes they all squirt at the same time. These systems are not referred to as EFI but rather DFI.

I only have one injected bike but have worked through it pretty thoroughly. It's a 1985 ZN1300.

There are two methods of adjusting the mixture. Fine adjustments can be done by tweaking the throttle position sensor very slightly. Larger adjustments require an adjustable fuel pressure regulator.

I have no experience with the aftermarket systems you mentioned.

Regards

KZQuixote

[PatsPOS]

Originally Posted by ratvespa

So, question is, do all the injectors fire at the same time? I cannon imagine that being to efficient. Did any cars do this or was this a 80's bike thing?

Well, rat...I dunno if all auto manufacturers did it, but in the earlier part of Ford's EEC-IV days, they had what was called "batch-fire", where four of the eight injectors (or three of the six on a 6-cylinder, or all four on a 4-cylinder) would get power simultaneously, then the other four. That sounds the most similar to what you have. Later on, Ford had a better idea and developed their own version of sequential fuel injection, where each injector sprayed independently.

I believe the Fords with SFI did better economically than the ones with batch-fire...but the difference was negligible. However (and with no scientific explanation!), my gut tells me that some kind of sequential injection on a bike engine would deliver significantly better economy than the batch-fire. Just my 2¢.

Pat