HFS-6 and Low-impedence injectors??

[Chris_M]

Richard,

I need some help. I finally got my new HSF-6 installed and it won't pass the initial power-up procedure. All goes well right up to step 3, with the key in position 2 the gauge behaves as expected but then all the light on the board come on and the system sprays at 100% constantly. I found that if I disconnect the injector (-) then it stops, however then I have no IDC signal. Does this have something to do with the fact that I am running low-impedence injectors? Is there a fix? I don't have the option to use high-z injectors because of their size.

Thanks.

Chris

[Richard L]

Hello Chris,

Can you tell me the model of your car.

High/low impedance injector should not make any difference.

[Chris_M]

Originally Posted by Richard L

Hello Chris,

Can you tell me the model of your car.

High/low impedance injector should not make any difference.

I am using an 034 standalone engine management system model IIc on a 1990 VW Golf Syncro with a 2.0 20V Turbo. The system has 4 injector drivers for sequential firing. I simply have the green wire from the HFS-6 yellow cable hooked up to the negative (-) side of one of the injectors. The other side of the injector is obviously hooked up to a keyed hot (+). I have traced the wire to be sure it is connected correctly and it checks out.

I agree the high/low impedance injector shouldn't make a difference, but I found another forum where it was blamed as the problem.

[Chris_M]

Richard,

I have done some more troubleshooting, here is what I know.

1. the injector negative I am tapping into is indeed the negative trigger from the ECU.
2. If the system is powered on with the green wire from the yellow RJ connected to the negative side of any injector it senses 100% IDC and injects water.
3. It makes no difference whether I use high or low impedance injectors.
4. If the same green wire is then disconnected the water injection stops.
5. When the system is powered on the same green wire has +12V when tested with a meter.

I need some help here. I have tested and re-tested everything and I am beginning to think the controller box is faulty.

Any ideas?

[Chris_M]

Any ideas? I would really like to have this system operational for my dyno appointment this weekend.

Thanks.

[Richard L]

If the HFS-6 sense a 100% DC on start up, there must be a voltage difference between the +ign switch and the fuel injection +. If the difference is more than 0.5v, the system will see this as 100%DC.

Relocate the red wire of the yellow harnesss to injector +. Leave the green wire at inj-. Let me know.

[Richard L]

I have one more question, if your are running low impedance injectors, do you use resistor packs in series with the injector?

If so, please tell me where the resistors are are wired in:#

1. Between the ign+ and injector
2. Between the injector and ECU

If there are no inline resistors, is the ECU a peak and hold type?


I don't believe there is anything wrong with th eunit, just need to correct signal matched. We often get these "mis-match" problem with modified fueling system.

[Chris_M]

There are no inline resistors. The ECU is designed to handle both low and high impedance injectors.

[Richard L]

It appeared that the system will be running in the "peak and hold" mode.

In this case, please put the red wire of the yellow harness to the Injector+ to minimise voltage fluctuation and false triggering. Pleas elet me know how it goes.

[RUFBTR]

Chris can you advise whether Richard's solution cured your problem.
I have an 87 Ruf BTR being re-done by TurboKraft and I need some help. I bought a NIB HFS-6 system from another member at Jeff's recommendation, I am using a motec M600 ecu and low impedance injectors, in this configuration the system will not trigger off the IDC because the voltage never drops on the injectors any suggestions?