[Old Goat Racer]

My in dash fuel pressure gauge is not working. How can I tell if the gauge or the firewall isolator is bad ? Fuel pressure is good at the regulator.
OGR

[25stevem]

Remove the gauge and apply air pressure to it.

[MatthewKlein]

Originally Posted by Old Goat Racer

My in dash fuel pressure gauge is not working. How can I tell if the gauge or the firewall isolator is bad ? Fuel pressure is good at the regulator.
OGR

If you know the operating range of the gauge you can apply the correct resistance to the gauge to test it. I've seen the volume control from an old radio used to simulate a sender. Attach a meter to the volume and adjust it to the correct resistance.

By the same method you can test the output of the sender with a meter while the engine is running.

If you decide to apply air pressure make sure you don't over pressurize it. Line pressure from an air compressor could ruin it.