low fuel pressure
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Senior User
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From: BAYVILLE
low fuel pressure
my 1990 ford van 302 5.0
has low fuel pressure i hooked up gage i turned key pressure drops
fast could it be a bad fuel regulator how can i tell if regulator is bad or not
it has one externally mounted pump and i gues two in tank
plus has dual funtion reservoir what does this reservoir do is like fuel filter
becaues this has two when i took a look under neth it looks like
it scews off what woild happen if scew it off
has low fuel pressure i hooked up gage i turned key pressure drops
fast could it be a bad fuel regulator how can i tell if regulator is bad or not
it has one externally mounted pump and i gues two in tank
plus has dual funtion reservoir what does this reservoir do is like fuel filter
becaues this has two when i took a look under neth it looks like
it scews off what woild happen if scew it off
Fleet Owner
Joined: Aug 2005
Posts: 23,667
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From: Easton,Ks
If you are saying that you hooked up a gauge and turn on the key and the pressure went up to about 40 PSI the pump quit after one second and then the pressure dropped to zero very quickly then I would say you have a bad check valve in the Hi-Pressure Fuel Pump on the frame.
No it is not a filter. In 1990 the dual function reservoir does not have a filter in it and if you take off the bottom cap you will mess up the big "O" ring gasket and they are hard to find.
You only have the one filter forward of the Hi-pressure pump.
No it is not a filter. In 1990 the dual function reservoir does not have a filter in it and if you take off the bottom cap you will mess up the big "O" ring gasket and they are hard to find.
You only have the one filter forward of the Hi-pressure pump.
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From: BAYVILLE
Originally Posted by subford
If you are saying that you hooked up a gauge and turn on the key and the pressure went up to about 40 PSI the pump quit after one second and then the pressure dropped to zero very quickly then I would say you have a bad check valve in the Hi-Pressure Fuel Pump on the frame.
No it is not a filter. In 1990 the dual function reservoir does not have a filter in it and if you take off the bottom cap you will mess up the big "O" ring gasket and they are hard to find.
You only have the one filter forward of the Hi-pressure pump.
No it is not a filter. In 1990 the dual function reservoir does not have a filter in it and if you take off the bottom cap you will mess up the big "O" ring gasket and they are hard to find.
You only have the one filter forward of the Hi-pressure pump.
why the fuel pressure relief valve do they go bad
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Joined: Dec 2001
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From: Louisville,Ky.
The reservoir allows fuel to only be drawn from one tank at a time. The pressure from the low pressure pump in the tanks, shifts the valve according to which ever tank that you select.
The check valve in the pump is supposed to only let fuel flow 1 way. If it goes bad, when the pump stops, it alloaws fuel to siphon backwards and lose pressure.
How is the pressure when it is running?
The check valve in the pump is supposed to only let fuel flow 1 way. If it goes bad, when the pump stops, it alloaws fuel to siphon backwards and lose pressure.
How is the pressure when it is running?
Fleet Owner
Joined: Aug 2005
Posts: 23,667
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From: Easton,Ks
Originally Posted by HENDEL
why the fuel pressure relief valve do they go bad
It maintains a fuel pressure from 32-43 PSI depending on the engine vacuum.
The diaphragm in the regulator can get a hole in it and allow fuel to go into the intake byway of the vacuum line. If you pull off the vacuum line and see fuel come out of the regulator then it is bad.
The Fuel Pressure Regulator.
Your Fuel System.
