HFS-3 with big fuel injecters
 

I hope every one is doing well.
My HFS-3 Installed and adjusted by my tuner on my BT Audi B5 S4, to inject 100% meth. Running +2 bar boost, the HFS3 is not activated until it reaches over 1 bar boost, I would like to make it come on earlier, tried by adjusting the THRES but it is cranked all the way counter clock already by my tuner. Is there any thing else that can be done to make it activate any earlier?
TJ

Re: HFS-3 with big fuel injecters
 

Is your big injector low impedance?

Re: HFS-3 with big fuel injecters
 

They are high impedance.

Re: HFS-3 with big fuel injecters
 

Are you triggering the H3 with IDC or MPS?

What are the sizes of your fuel injectors? If they are very large, your duty cycle could be quite small. If this is the case, you can multiply the input by x1.5. Refer the instruction sheet came with the green harness.

Re: HFS-3 with big fuel injecters
 

Can you measure the voltage on test pin 16 relative to the "ground" pin.

1. pre-crank
2. during cranking
3. engine started and idling
4. light cruise
5. mild acceleration
6. WOT.

Re: HFS-3 with big fuel injecters
 

The injectors can flow 83lb @ 3 bar.
According to my tuner the system triggers with both IDC and MPS?

Re: HFS-3 with big fuel injecters
 

What will multiplying the input do to Failsafe?

Will look for the instruction sheet but if in case it's lost or missing, can it be found on the net somewhere?

Re: HFS-3 with big fuel injecters
 

You cannot do that, either IDC or MPS. not boith. Perhaps that is the problem.

Re: HFS-3 with big fuel injecters
 

Multiplying does nothing to the failsafe. The instruction sheet is inside the green harness bag.

Re: HFS-3 with big fuel injecters
 

That's what I thought, I installed another HFS-3 my self on my other car with 630 cc injectors and have no issue with early trigger with IDC only.

Will check with my tuner if he had actually connected both IDC and MPS.