Question About Stock Fpr
02-19-2004, 02:55 PM
#2
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Join Date: Oct 2001
Location: Peoria, AZ
Posts: 10,906
I think it should. I have never tested it though. I remember pulling the vac line off on an n/a one time. And if the fpr wasn't bleeding off fuel as it should, the car I would imagine would have either started to run dog rich or the injectors would have started leaking since fuel pressue would start to sky rocket.
02-19-2004, 06:07 PM
#5
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Join Date: Apr 2002
Location: IL
Posts: 2,930
with no vacuum line attached they should still flow fuel.
no vac line == atmosperic pressure, so having no vacuum line connected is comparable to the condition your FPR experiences around WOT (it will still have around 1-2inHg due to the throttle plates and air filter etc though)
on my setup WOT is like 0 inHg to the MAP sensor.
the fpr is supposed to compensate for vacuum on the other side of the injectors (and boost on a t2), so when the fpr gets 0 vacuum, it is supposed to regulate the static fuel pressure.
when it gets N vacuum, it regulates static fuel pressure - N.... when it sees boost, it regulates static fuel pressure + N psi boost.... so yes, it definitely should flow fuel @ atmospheric.
no vac line == atmosperic pressure, so having no vacuum line connected is comparable to the condition your FPR experiences around WOT (it will still have around 1-2inHg due to the throttle plates and air filter etc though)
on my setup WOT is like 0 inHg to the MAP sensor.
the fpr is supposed to compensate for vacuum on the other side of the injectors (and boost on a t2), so when the fpr gets 0 vacuum, it is supposed to regulate the static fuel pressure.
when it gets N vacuum, it regulates static fuel pressure - N.... when it sees boost, it regulates static fuel pressure + N psi boost.... so yes, it definitely should flow fuel @ atmospheric.
02-19-2004, 07:39 PM
#7
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Join Date: Apr 2002
Location: IL
Posts: 2,930
Originally Posted by j9fd3s' date='Feb 20 2004, 01:33 AM
i just checked mine, i cant blow thru it
the fpr will see atmo pressure for a short time when transitioning from vacuum to boost on a turbo car, it definitely has to flow fuel under this condition.
02-19-2004, 08:31 PM
#9
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Thread Starter
Join Date: May 2003
Location: Greensboro, NC
Posts: 283
what the hell are the chances that i would get 2 non-functioning fpr's!!!!
i really must have the worst luck ever!!!!
Loi
o, and i'm testing them cause my car won't start and i'm pretty sure its a fuel thing cuz it starts when i spray starting fluid into it.
yeah, and my car won't turn over when its on the ground but will when its on jackstands. thats a whole different problem though....damn project cars, damn them to hell!!!!!!
i didn't mean that....
i really must have the worst luck ever!!!!
Loi
o, and i'm testing them cause my car won't start and i'm pretty sure its a fuel thing cuz it starts when i spray starting fluid into it.
yeah, and my car won't turn over when its on the ground but will when its on jackstands. thats a whole different problem though....damn project cars, damn them to hell!!!!!!
i didn't mean that....
02-19-2004, 08:40 PM
#10
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Join Date: Nov 2002
Location: Honolulu, Hawaii USA
Posts: 925
Sure...
Mazda spec is 35psi at vacuum or under -"0"
At "0" it supposed to step up to 40psi.
If this is a turbo FPR, then it's a 1:1 ratio for boost versus pressure.
i.e. - at 10psi of boost, the fuel rail pressure should be 40psi + 10psi = 50psi.
-Ted
Mazda spec is 35psi at vacuum or under -"0"
At "0" it supposed to step up to 40psi.
If this is a turbo FPR, then it's a 1:1 ratio for boost versus pressure.
i.e. - at 10psi of boost, the fuel rail pressure should be 40psi + 10psi = 50psi.
-Ted