Sorry to have so many questions. My truck been sitting for a while and now trying to get the bugs out. Fuel and oil pressure gauges not acting right. Fuel pressure reads 100 all the time and oil bounces around to the point you can hear it. I changed the oil so wondering if maybe air in the line. What's the fix for this? Should they be replaced? I know the fuel is old. Thanks

 

If the fuel pressure sender is screwed right into the regulator housing they take a pretty good beating there. Many people use a short piece of line to mount it away from the engine vibrations. I saw one the other day where they used an extension from a manual grease gun to "remote mount" the sensor. If you like the gauges you have I would try new senders first. If the fuel pressure stays at 100 all the time the gauge may be stuck because the pressure bleeds down pretty quickly after shut down.

 

Both the gauges fall back to zero when turn the key off. The op tries to work at times and then not. So you would replace the sendin units before the gauge?

 

Yes to sending units. When my Isspro sending unit died the gauge would peg to 100psi, but would correctly home to zero and sweep the full range at startup. You could pull the wiring connectors and both ends and make sure there isn't a short between the connectors. If the sending unit is 3 wire I'm sure you could power it and see what voltage it's pushing to the gauge, and ohm it out. The manufacturer has to have some kinds of specs on it, and that would narrow it down to sending unit, wiring, or gauge.

 

Thanks guys