testing fuel pressure
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From: Maple Ridge, Canada
testing fuel pressure
I'm trying to test fuel pressure and I know there is a plug in the back of the filter but I don't have a fitting that will work. My shop manual says there is a shaeder valve in the system (I do have that fitting). Does anyone know the location of or know if the shaeder vale actually exists? my diagram gives no clues to the location.
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From: Monterey Bay. CA
I have never saw the valve you are referring to but that does not mean it is not there. Not sure on that and dont really understand where it could be in the system as I am going over the fuel lines from the tank to the valley in my mind. Maybe someone might know what this is.
I have always just bought a sending unit and put in the back of the fuel bowl housing for a gauge in the cab.
Do you think you are dropping fuel pressure?
I have always just bought a sending unit and put in the back of the fuel bowl housing for a gauge in the cab.
Do you think you are dropping fuel pressure?
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From: Payson, AZ
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From: Maple Ridge, Canada
Yeah, I didn't think there was one, but I thought I'de ask here. From my diagram It looks like it may be on the passenger side of the valve cover, but I've never noticed one.
I do think I'm loosing fuel pressure as the truck is parked. It gets harder to start the longer it sits, even on the hottest summer day. Then it idles and runs rough (like 6 cyl rough) until the engine is warmish and I step on the pedal a bit. Then I can feel the truck just smooth out and run fine, I think that is the air clearing. I've been through the gp's, gpr, blah blah, beat that one to death. I wanted to make sure I didn't miss something simple.
I do think I'm loosing fuel pressure as the truck is parked. It gets harder to start the longer it sits, even on the hottest summer day. Then it idles and runs rough (like 6 cyl rough) until the engine is warmish and I step on the pedal a bit. Then I can feel the truck just smooth out and run fine, I think that is the air clearing. I've been through the gp's, gpr, blah blah, beat that one to death. I wanted to make sure I didn't miss something simple.
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Shraeder valves were on the OBS trucks. Sound like your High Pressure Oil reservoir is bleeding down maybe.
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From: Maple Ridge, Canada
I checked the oil level and it was 1" from the top, even before a good start. It's supposed to be 3/4", but I don't think it's an exact science.
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paysonpsd, thanks for the link, I might just order one. I was hoping to get this done today though, and not wait for parts...
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From: Maple Ridge, Canada
never thought of that, but last night I did drain it before taking the plug out. It's hard to guess at volumes, but it seemed to be a normal amount of diesel and it was sitting for a few days previous.
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Ok, got my fittings from Guzzel last night! hooked up the fuel pressure gauge and something doesn't make sense. I turn on the key, wait to start, and the gauge climbs quite quickly to 55-60psi. it wavers a bit and after about 30 sec the gauge drops like something has openned. Then it sits at about 15psi. I tried the engine hot and same thing. While engine is running the psi is a solid 60. Any ideas?
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From: Buffalo, NY
Sounds right to me.. The system only pressurizes for a few seconds on Key on. You can hear the pump turn on when you turn the key on, But shortly after the pump stops, then the system bleeds down. It won't sit there at 55 unless you start it. Sounds like you are working good. I didn't know it stops bleeding at 15psi, I thought is would drop to 0 but i guess you will need something to start it.
