[Richard L]

Thanks for the voltage, nice.

I can see the problem. Your 12V rail volatge is very low compared to a normal car. The H3 is comparing the rail voltage against the injector(-) voltage if it lower than 0.5V, it is considered as injector activation.

We have a few solutions:

1. Beefing up 12V cable size to the fuel pump and injectors. It is good practice anyway to have as little drop in voltage as possible.

2. Modifing the HFS-3 to allow a wider detection window. I think in your case, 2V is about correct.

I suggest doing solution #1 first, allowing the voltage on test pin#5 less than 0.5V.