Oil pressure gage or sending unit?

[Lynn Kirkpatrick]

Does anyone know how to troubleshoot the oil pressure gage and sending unit on a '68 MGB GT? The gage with the stock setup reads scary low. I "T-ed" in a non-electrical gage and pressure shows 80+ cold and 50 or so warm idling, so I think the motor is OK.

Is there a way to ground the sending unit wire, or put a resistor in line with ground to check which is bad?
Thanks, boys and girls
Lynn

 

[MGZT260]

More than okay. Sounds actually a little tight to me. One manual states 50-80 psi running, and 10-25 at idle. Not that 50 at idle will necessarily hurt anything just that it might be an indication of plugged passages somewhere.

You can , knowing you do have pressure (even though I think a little high) run engine with electrical tester conneced to sender, check for changes in resistance. If no change is noticed at all with cahnges in rpm or between running and not then buy a new sender. If it shows different readings then troubleshoot the wiring from sender to gauge.