4th gen with 5th gen fuel rail - damper or no damper?
05-23-2005, 09:26 AM
#1
3.5 in the works
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4th gen with 5th gen fuel rail - damper or no damper?
I did a bit of searching and it seems most that have done the 00VI swap using the 5th gen LIM and fuel rail have gotten rid of the DE-K fuel damper and just left the regulator. I'm trying to understand what effect the damper has on the system and whether/why it's best to keep it or lose it.
According to the FSM's I have, the pressure through the regulator is supposed to be the same on both the 4th gen and the 5th gen (approx 34-43 psi, depending on manifold vacuum). Also, the part #'s for the fuel pump are the same even though the casings are different so is the pump putting out the same pressure on both gen's? Does anyone have a definitive answer as to the function of the damper? What would be the reason to keep/not keep it?
PS--I took a quick look but if I've missed this in the stickies anywhere please point me in the right direction. Thx.
According to the FSM's I have, the pressure through the regulator is supposed to be the same on both the 4th gen and the 5th gen (approx 34-43 psi, depending on manifold vacuum). Also, the part #'s for the fuel pump are the same even though the casings are different so is the pump putting out the same pressure on both gen's? Does anyone have a definitive answer as to the function of the damper? What would be the reason to keep/not keep it?
PS--I took a quick look but if I've missed this in the stickies anywhere please point me in the right direction. Thx.
05-23-2005, 09:38 AM
#2
Originally Posted by DandyMax
I did a bit of searching and it seems most that have done the 00VI swap using the 5th gen LIM and fuel rail have gotten rid of the DE-K fuel damper and just left the regulator. I'm trying to understand what effect the damper has on the system and whether/why it's best to keep it or lose it.
According to the FSM's I have, the pressure through the regulator is supposed to be the same on both the 4th gen and the 5th gen (approx 34-43 psi, depending on manifold vacuum). Also, the part #'s for the fuel pump are the same even though the casings are different so is the pump putting out the same pressure on both gen's? Does anyone have a definitive answer as to the function of the damper? What would be the reason to keep/not keep it?
PS--I took a quick look but if I've missed this in the stickies anywhere please point me in the right direction. Thx.
According to the FSM's I have, the pressure through the regulator is supposed to be the same on both the 4th gen and the 5th gen (approx 34-43 psi, depending on manifold vacuum). Also, the part #'s for the fuel pump are the same even though the casings are different so is the pump putting out the same pressure on both gen's? Does anyone have a definitive answer as to the function of the damper? What would be the reason to keep/not keep it?
PS--I took a quick look but if I've missed this in the stickies anywhere please point me in the right direction. Thx.
I believe the return line differences have something to do with it.
05-23-2005, 09:48 AM
#3
Look up what a fuel damper is and it will tell you why you should have one, however the reason 5th gens. have one and 4th gens don't is because 4th gens have an inline fuel filter that sort of acts like a damper vs. the 5th gens. only having the intank fuel strainer....IIRC.
05-23-2005, 10:15 AM
#4
3.5 in the works
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Originally Posted by IceY2K1
Look up what a fuel damper is and it will tell you why you should have one, however the reason 5th gens. have one and 4th gens don't is because 4th gens have an inline fuel filter that sort of acts like a damper vs. the 5th gens. only having the intank fuel strainer....IIRC.
05-23-2005, 10:35 AM
#7
3.5 in the works
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Originally Posted by IceY2K1
Cool.....
In short, 4th gens. don't need the 5th gen damper, since 4th gens. already have a damper between the rail/pump, ie the inline filter.
In short, 4th gens. don't need the 5th gen damper, since 4th gens. already have a damper between the rail/pump, ie the inline filter.
05-23-2005, 10:41 AM
#8
Originally Posted by jmeister
So would leaving the damper in place when doing the swap cause any issues? Possible too low fuel pressure?
Leaving the damper in shouldn't have any effect on fuel pressure, other than damping pressure oscillations.
05-23-2005, 06:48 PM
#10
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I am running the 3.5 fuel rail with the 1995 FPR and a 300zx Fuel Filter. Maybe the 300zx fuel filter doesn't have that valve that prevents gas from going back to the tank, because sometimes I turn the key, hear the pump, and have to wait a few seconds before starting it.
One end of the rail has a 3.5 damper (or at least that's what it looks like) and the other has the 95 FPR. Anybody got ideas? Is it the fuel filter?
One end of the rail has a 3.5 damper (or at least that's what it looks like) and the other has the 95 FPR. Anybody got ideas? Is it the fuel filter?
05-24-2005, 09:16 AM
#11
Could be the filter takes time to fill up, which adds time for the system to pressurize.
Try bypassing the filter and see if that helps.
Try bypassing the filter and see if that helps.
Originally Posted by JClaw
I am running the 3.5 fuel rail with the 1995 FPR and a 300zx Fuel Filter. Maybe the 300zx fuel filter doesn't have that valve that prevents gas from going back to the tank, because sometimes I turn the key, hear the pump, and have to wait a few seconds before starting it.
One end of the rail has a 3.5 damper (or at least that's what it looks like) and the other has the 95 FPR. Anybody got ideas? Is it the fuel filter?
One end of the rail has a 3.5 damper (or at least that's what it looks like) and the other has the 95 FPR. Anybody got ideas? Is it the fuel filter?
05-31-2005, 09:36 AM
#18
Originally Posted by Nismo3112
What was your problem?
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