batch fire injector sequence

[zguy36]

Just some ideas running through my head... I remember reading that the fuel injector for the bosch L-jetronic system uses a batch fire sequence. ('83 turbo ecu) I do not remember if the injectors are fired all at once, or if there is two groups. I don't have access to my oscilliscope right now, so I can't test it to check. If anyone knows if it is one or two groups, let me know.

-jeremy-

[sims76]

Zguy,

 

They are batch fired, all at once.

 

The following link is a good read about the reality of batch vs sequential.

 

http://www.sdsefi.com/techseq.htm

[zguy36]

The reason I wanted to know the firing sequence of stock injectors is because I had an idea to increase fuel flow with smaller injectors. Yes, I did say smaller. I hooked up my meter to measure duty cycle for the injectors and the duty cycle maxes out at 42% I found this to be quite weak, but that is with a good AFM wide open. I thought that if the injectors fire in two batches, to rewire them so that when a signal is sent out to fire the injectors, that it fires all six instead of only three. This would double the fuel input, since it would be firing twice as often. The stock injectors are 2.2 ohm and higher inpedence injectors would be needed to account for running six injectors on the driver instead of three. For 19# injectors have a much higher impedance and would not overload the driver.

I did not find a schematic of the L-jetronic for the turbo 280zx ('83), but every other schematic I found showed that the injectors are fired in groups of two. This could still work with wiring the driver to fire four injectors instead of 2, but diodes would be needed..

 

Has anyone else thought of this, or tried this?

-jeremy-

[Sean73]

When the engine is over 3000 RPM, the ECU already switches to simultaneous injection (all injectors firing at once).