Archived Lost all fuel pressure while installing gauge

[tconerly]

While installing Geno's Westach fuel pressure gauge with LAHF line,

I lost all fuel pressure. Problem began when connecting open ended line

to schrader valve on VP44. Diesel running normal prior to this inst.

Question... . When removing the fuel filter cap on o1, should the

lift pump loose prime? I have lost prime all the back to tank.

Have 85K on truck with no prior problems.

 

[B.G. Smith]

Removing the fuel cap should not cause a problem but opening the fuel line anywhere after the lift pump to the VP would let the fuel drain back to the tank especially if the fuel level was low in the tank, it should pick right back up though if the lift pump is working, of course there will be air trapped in the line up to where the line was opened. bg

 

[AKAMAC]

Have you tried bumping the starter to let the LP run for 20 seconds? Also make sure the O-ring didn't bunch-up/ break. Take the FF cap off and lube the O-ring and threads then reseal it.

 

[tconerly]

Thanks guys for answering my post.

Problem was resolved by pressurizing fuel tank and energizing

lift pump. Idle fuel pressure is 13psi, WOT to be checked later.