IDC sensing HSF-3

[kellygnsd]

I have a HSF-3 system that I'm wiring into my STi. I'm running a Link G4 standalone ECU and I think the fule injector carrier frequency is different than stock. Currently I'm tapped into on of the injectors with the inj- lead but with the threshold pot fully anti-clockwise meth injection starts at like 1.5% IDC. I thought it wasn't supposed to trigger until 12% at the minimum setting.

I would like to use a PWM table in my ECU to control meth flow but I need to know how to wire that into my Link. Do you have any circuit diagrams of the inj+ and inj- wiring. What is the difference between inj+ and inj- and if I only have a low side PWM drive, how do I wire the Link so I can use custom flow tables based in the ECU. Thanks again.

[Richard L]

Just wire the green wire of the grey harness to the LINK 's low switch output, that is all. Use ~50Hz to 80Hz region for the PWM. Red wire remains the same location as before.

[kellygnsd]

Thanks again Richard.

[kellygnsd]

Richard,

I have fairly large injectors, around 1200cc/min but as stated above I'm driving the HSF-3 controller via an aux output instead of from the actual fuel injector signal. Should I still solder a bridge on the 1.5x gain pad and break the 1.0x bridge or will the 1.0x gain be sufficient?

It seemed like when I tested the system I wasn't able to get below 4 bars on the flow sensor with injection triggering at about 7.5%. Is that about right with the .9 and .8 nozzle installed?

[Richard L]

It all depends on how much of 1200cc injector is used. If you are using the full 4800cc/min, then you don't need to alter the pre-amp gain to x1.5.

But if you are only using up to 60-70%, then do make the x1.5 gain.

I await for your answer first so I can answer the second question.

[kellygnsd]

I will probably use 80 - 85% of the available IDC.

[Richard L]

That is a great deal of power for a sti? Or you are running E85?