Is there a way to check oil pressure from the sending unit with a multimeter? Gauge is not showing pressure, yet the wire looks to be in good condition. I'm wondering if there's a certain volt output depending on the amount of pressure.

 

it's a grounded sensor, meaning the resistance to ground is modified as pressure rises so you need an ohmmeter not a voltmeter.

i really haven't bothered to test one, the easy way to test it is to ground the wire off the sensor and check the gauge to verify the gauge is working. if there's oil in the filter then there is pressure. if there is no sign of pressure on the gauge but oil is in the filter then you almost are guaranteed that it is just a bad connection to the sender unit or possibly a faulty sending unit itself, although i rarely see them fail but i do often see the connector packed with dirt and grease which isn't the best at creating continuity.

 

Have you tried removing the plug to the sender and cleaning it thoroughly? Reconnect after placing a fair amount of dielectric grease to the plug. I did and it was the key to remedying my problem.

 

Outright failure- as in, "spewing oil everywhere"- may be rare but decreasing accuracy is not.
Basically a mechanical device- very similar in action to a fuel level sender, in fact- as the sending unit's diaphragm ages it produces lower and lower pressure readings.
Everything still works but the data is wrong.

 

perhaps, but not enough for me to even really notice or care about.

"does it have oil pressure?" yep

 

Check for the little black box/condensor bolted to the slave (or other location if someone didn't put it back) could be dangling.

 

Here's a thread that covers most of this.

https://www.rx7club.com/showthread.p...=potentiometer

With the pot trick I laid out you can check your gauge and you can use a mityvac or other reasonably reliable pressure source to input pressure to your oil pressure sender and read the ohms listed on the diagram HAILERS included.

Good luck.