Dummy oil pressure gauges suck. Swapping the gauge and sender also sucks. Get a real oil pressure gauge for a lot less suck:
1. Have real oil pressure sensor
2. Buy $6 worth of 180Ω 1-watt resistors
3. Replace both resistors in stock gauge with 180Ω resistors
4. Rewire the sender wire to a spare PWM output at your ECU
5. Use generic PWM output to control your gauge: 250hz, 100% duty = 0PSI, 0% duty = ~65PSI* for me, but easily adjustable via curve
6. Profit

* You can probably play with resistor values to get more range. I found 180Ω gave a wider range than 270Ω but did not test further.

 

Interesting. Did you verify actual pressure with a mechanical gauge vs what the modified gauge was reading? If not I have a spare NA oil pressure gauge I can try this with. Though I would use a 3 wire potentiometer to see what final resistance value range could be.

 

I have a 3-wire analog oil pressure gauge wired to the MegaSquirt which I used as a reference. Haven’t confirmed that the readings match with a mechanical gauge but as long as I have the correct voltage curve for the sensor that shouldn’t be necessary. I just used Generic PWM and tested which duty cycles resulted in which readings on the gauge and then create a curve of oil pressure vs duty accordingly.

 

thanks!
cool stuff, i already have an oil press wired in, cool to be able to control my oil press gauge with the MS