I'm not sure that I'm doing this right.  I don't want to buy, and then crowd my panel with, separate gauges for oil temp and pressure, so I've decided to wire them into my MegaSquirt.  The upside is that will enable me to log them.  To do this, I need resistance curves for the sensors.

The temp was no problem.  Measure it at room temp, after it has been in some ice water for a while, and then boil it for a while.

The pressure sender, I finally settled on just connecting it to my air compressor while varying the pressure.  At ambient, I got an open circuit.  Opened the regulator up to 30psi, and I got 39 ohms.  Then it stayed at 39 ohms, all the way up to 100psi.

I don't think this is the way the pressure regulator is supposed to work, but I'm willing to be corrected if I'm wrong.  Should I just order a pressure sender?