bypass hpdi system

[boscoe99]

I think better to monitor pressure on the PC. That way you don't have to install an interface adapter cable, or jerry rig with paper clips/probes/etc., to monitor voltage and then convert voltage to pressure.

I am not aware of any Yamaha chart that converts voltage to pressure. The tune up book simply provides a voltage value for idle pump pressure. No guarantee however that idle pump pressure will be the same as high RPM pump pressure. Should be but...

More than two ways to skin this cat.

[rodbolt17]

at ALL RPM and load the HP pump sensor voltage should be about 3.2V.
it is that simple.
published SM data.

[boscoe99]

at ALL RPM and load the HP pump sensor voltage should be about 3.2V.
it is that simple.
published SM data.

Yes. I know. Should be is the operative word.

But given that the pump output has a wide range when seen in YDIS (plus or minus 116 psi for a one pump HPDI) I don't think that range will be able to be seen in voltage to just one decimal place.

Hook up the lap top and come into the modern world.