fuel pressure gauge

[dodgedougak]

Is anyone running a fuel pressure gauge on their multi-fuel? I am trying to figure out what pressure range to use. TM 9-2910-226-34 seems pretty clear at first 3 to 5 psi between the tank and the IP gear pump, then 60 to 80 psi between the IP gear pump and the hyd. head. Then the TM gets real unclear. What is clear is that they are talking pressures while testing an IP on a test bench. I would like to have a pressure gauge in the fuel line after the primary and secondary filters, to monitor the in-tank pump performance and filter condition. Anyone have experience with this?

 

[martinwcox]

I have one fitted by the previous owner, 0 - 100 PSI plumbed into what was the bleed screw between the secondary fuel filters.

Shows 40 psi at idle and around 60 psi when on the move.

 

[dodgedougak]

fuel press gauge reply

Thanks for the reply. That is great to know. I had spotted that bleed port as a good place to add a fuel pressure gauge line. Now I know what range of gauge to buy. Old school, but I like to see my fuel pressure, as well as exhaust temp and boost. so am setting up to do all three.

 

[SpecialK]

I put a digital gauge on the inlet and outlet of the primary to monitor the pressure drop(that way it don't have to change my filter in a parking lot) it's been working well. Right there with you on EGT and Boost, put those in at the same time!

 

[dodgedougak]

Thanks for the reply. What kind of pressure do you see at the primary filter?

 

[SpecialK]

It typically runs between 5 and 9 PSI depending on fuel type and temperature. A new filter has about a 1/2 PSI drop and when it gets up around 3 I start noticing power loss.

 

[dodgedougak]

Thanks, SpecialK. Now that I have some pressure ranges, I can get my gauge package finalized. Have a great New Year.

 

[Gastrap]

I have one fitted by the previous owner, 0 - 100 PSI plumbed into what was the bleed screw between the secondary fuel filters.

Shows 40 psi at idle and around 60 psi when on the move.

Same place here, I put one in when working on it & just left it there.

 

[SasquatchSanta]

I run two gauges. one between the tank and the primary filter and another between the primary filter and secondary filters. They run between 3 and 7 depending how far my foot is in the pump.

 

[steelandcanvas]

Somebody straighten me out, I'm getting mixed messages here. One Gentleman says he has a 0-100 PSI gauge, reading between 40 PSI at idle and 60 PSI running. This is tapped into the bleed screw between secondary and final fuel filters. Another Gentleman says his runs between 5 ans 9 PSI, depending on temperature and fuel used. Another sees between 3 and 7. What gives? I'm lost!

 

[SpecialK]

My pressure readings are after the tank pump and before the IP gear pump. The higher pressure gauges come in after the IP gear pump. Not every pressure is going the be the same between trucks, there's many variables that come into play.

 

[73m819]

I would think ONE gage AFTER the filters would tell you when the filters were statring to plug

 

[SpecialK]

One gauge would suffice, but only to a point. This morning when it was 30 degrees my tank pump was pushing 6.5 PSI, after a 2 hour errand run around town the diesel was nice and warm and it was pushing 8.5 PSI. Temperature makes a big difference! That is why I chose 2 gauges so I could monitor the actual pressure drop across the filter. That... and I like to make things complicated and know as much info about my truck as possible!

 

[dodgedougak]

Steelandcanvas-
I am assuming that the 5-10 psi reading is the output side of the in-tank pump (whichever side of the primary filters you are on). I also assume that the 40-60 psi readings are between the IP mounted gear pump and the IP. That is close to what the TM says you should see on the test bench. I am on my ship and can't get to my truck to trace the lines, but that would indicate to me that the secondary filters are in the line after the IP mounted gear pump.

 

[Wildchild467]

If i am running WMO in the truck, what gauges would be needed to moniter my primary filter? My in tank pump is new and works great. my question is, with the tank cold and having around 75%-100% used motor oil, how much pressure will I have before and after my primary filter? With diesel, it is much thinner and flows easier. Im thinking with WMO my in tank pump will not have enough pressure to maintain that pressure across my primary filter and to the injection pump at operating RPM. For that reason, I am thinking there might be a little suction on the line between the injection pump and primary filter. Does anybody know if this could be true? another question I cant seem to find the answer to is what GPM the gear pump is that is on the injection pump? When I am driving down the road, what kind of fuel flow am i getting at 2200 RPM? this might help me understand what pressures/vacuum i have on my primary filter. I know if it clogs, it will have a vacuum on the filter between the IP and primary filter. So with a clean 10 micron primary filter, using 75%-100% WMO, what vacuum or pressures might be present in my system? I hope that all makes sense.