Fuel Pressure checks

[SKS]

Hello Group,

Decided to check to output pressure from the lift pump on our Cummins 2000 6BT with 950 hrs. Borrowed a test kit and installed a banjo bolt adapter with a Schrader valve at the end of the solid fuel line before the engine mounted filter. Pressure was 8psi. Manual says .5-10 psi so I believe I’m good.

Anyway, I would like to keep a similar adapter in place for easy checks going forward without overcomplicating it.

I could buy a kit an just leave the adapter installed (maybe with a cap) but I wonder about the longevity, quality and material compatibility of a test kit part.
I don’t need a permanent fuel pressure gauge just easy access to an adapter or sending unit.

Any suggestions?

Thanks in advance.

Steve

 

[Aquabelle]

Hello Group,

Decided to check to output pressure from the lift pump on our Cummins 2000 6BT with 950 hrs. Borrowed a test kit and installed a banjo bolt adapter with a Schrader valve at the end of the solid fuel line before the engine mounted filter. Pressure was 8psi. Manual says .5-10 psi so I believe I’m good.

Anyway, I would like to keep a similar adapter in place for easy checks going forward without overcomplicating it.

I could buy a kit an just leave the adapter installed (maybe with a cap) but I wonder about the longevity, quality and material compatibility of a test kit part.
I don’t need a permanent fuel pressure gauge just easy access to an adapter or sending unit.

Any suggestions?

Thanks in advance.

Steve

Why do you think this is such a risk that it needs regular monitoring ? I've only ever heard of this test being done on Cummins B 5.9s as part of diagnosing low power symptoms and even then it is way down on the checklist. And you have low engine hours to boot. What gives?

 

[SKS]

Good question. During the process of investigating an air leak in the fuel system I read about low lift pump pressures and resulting damage to injector pump.
I figured a lift pump check would be worthwhile. Since it would be nice to know about a failing lift pump in advance, why not be able to easily check it?
The test kit adapter makes it easy but I kind of doubt it’s a permanent part.
So, why not query the group for thoughts?

 

[O C Diver]

I have a Dodge 2002 pickup with a Cummins 6BT 220 HP engine. The lift pump had worn enough where there was diminish pressure and flow which trashed the injector pump. Later models have a warning light on the dash for low fuel pressure. The diesel shop I was using at the time, installed a pressure sensor and idiot light near the dash that would illuminate when you turn the key on and go out above a specific fuel pressure.

The pickup has an electric fuel pump that lasts around 80,000 miles. The next time it started wearing out, the mechanic I currently use, suggested going to an electric fuel pressure gauge and an aftermarket fuel pump. This pump lasted about 200,000 miles and I could see it becoming erratic before the pressure dropped off. Have thought about installing a fuel pressure gauge on my trawler.



Sensor on the left is idiot light. Fuel gauge sensor is on the right.



Ted

 

[SKS]

Thanks Ted!

 

[jleonard]

Those truck engines have a different pump than the 2000 era marine engine. The marine engine is not sensitive to lift pump pressure like that truck pump is.

 

[O C Diver]

Those truck engines have a different pump than the 2000 era marine engine. The marine engine is not sensitive to lift pump pressure like that truck pump is.

It's not pressure, it's volume. I believe the marine injector pump still requires fuel volume to cool the injector pump. Loss of pressure would indicate a reduction in volume as it is no longer returning fuel to the tank. I believe both systems incorporate a bypass valve to maintain a minimum pressure.

Anyway, one more benchmark to help alert you to a problem before it shuts you down.

Ted