I was trying to follow Infidels advice on how to make a fuel pressure gauge but without success thus far. My wife was watching the gauge in the cab while I was opening the needle valve. She said it made a small twinge and then didn't move again while I was slowly opening the valve. I also had a leak in the cab by the gauge. I only tightened the nut 1/2 turn past finger tight as per instructions I tightened it a little further after I noticed it was leaking only to make it leak faster. So I took it apart and only tightened it 1/4 turn past hand tight. Leaked again slowly tightened it more seemed to stop but over a little time started again. The gauge is for oil press it never worked so I guess I will try another gauge tomorrow. Anybody else make one of these work?

John

 

You really don't open the needle valve that much. Like 2mm from full close.

 

I followed Infidel's post about installing a fuel pressure gauge and it came out well.I used a water pressure gauge but it shouldn't make any difference.I also had a small leak in the connection at the gauge so I cut the old ferrel off and installed a new one and that took care of it.

 

Shelley's advice is right on, replace the ferrel.
The ferrels tend to get distorted and don't usually seal with retorquing.

As for no pressure reading, I would suspect that either the gauge or your overflow valve is bad. Or could be that the leak is venting all your pressure.

 

New gauge, new ferrel. No leaks and this gauge works. I have about 10 psi at idle and by the time I am going 45mph it has gradually gone down to 0 psi. Is my lift pump bad?

John

 

Mine leaks at the banjo bolt. What is the best sealant?

 

Pinch the return fuel line behind the fuel filter, if your pressure does not come up, probably the Lift Pump, fuel pre-filter, or fuel filter. If it does come up, probably your overflow valve on the P7100.

Should be 20-25 at idle and 35 or so at speed, IIRC.

 

Permatex #2 or anti-seize.

 

I used grey anti-seize and it leaks, will try the permatex.

 

Pinched the return line and at idle the fuel pressure got up to 50 psi in about 10 seconds and was rising quickly so I shut down the engine. So I guess it's time for a new overflow valve. Thanks for your help guys.

John