BearKiller

I got my fuel-pressure gauge plumbed in, between the filter and injection-pump.

I didn't replace the filter, as it hadn't been on there very long.

I installed the Glacier Big Line Kit, with a TEE tap for the gauge line.

On this TEE, I installed a BALL-VALVE, and a SNUBBER, then the gauge line.

When first installed, the gauge was holding 4 PSI.

With the engine idling, I shut off the BALL-VALVE, then shut down the engine and left it be for several hours.

Then, when I checked the gauge, it was still holding 4 PSI, signifying that there are no leaks in the gauge/line.

I opened the BALL-VALVE and the gauge immediately dropped to zero.

On a three hundred mile trip, the gauge stayed steady at 4 PSI, up hill and down, idle or full throttle; occassionally I saw it creep to 5 PSI, but really wasn't doing anything different.

The original 1989 diaphragm-type mechanical fuel-pump is still on the engine.

How do my observations compare with others' experience??

Thanks.

wannadiesel

Sounds like you have an acceptable lift pump. A real healthy diaphragm pump will do 7-8 psi, but there's nothing wrong with being able to hold 4 psi under all conditions.

The system does not hold pressure when the engine is off, this is normal.

Ace

That pretty much exactly how my diaphragm pump behaved.

BearKiller

I assume that, since the VE can draw it's own fuel, to an extent, should the lift-pump be completely dead, a pressure/vacuum gauge would show a vacuum, correct??

Short Box

If a diaphram pump does 7-8 psi and a piston lift pump does 4 psi, what is the advantage to a piston pump? Just wondering cause the truck I just bought seems wet around the lift pump.

Ace

Piston pump is rated for 15psi. The 4psi referred to above would be for the diaphragm pump.

wannadiesel

In the case of a dead pump, yes.