Oil pressure sender (not switch)

[cclxxxz]

Hello All:

Does anyone know how to test an oil pressure sender for a 1993 Toyota 4-cylinder, 4wd pickup? Mine measures 50 ohms with the engine running (any rpm) and infinite with the engine off. Does anyone have a chart of sender resistance vs. pressure or resistance vs. engine rpm for this sender? It seems to me that the resistance should be a function of pressure.

Thanks in advance!

[JeremyH]

You might try cleaning the electrical connector on your oil sending unit. Any gunk in there will cause a change in resistance which means funky guage readings. Simply unplug the connector and clean the female ends with electric motor cleaner and plug back in. Do this a few times (unplug, clean, plug in, unplug, clean, plug in...) and then finally fill the holes (female end) with some dielectric grease. This should fix your problem. If not, then your sending unit is bad and probably needs to be replaced.

Hope this helps,

Jeremy