I know what it does. I guess the technical term would be a one-way check valve or a pulsation dampener. It keeps the fuel rail pressurized when you turn the key on and the pump primes for a second then shuts off. This little thing keeps the pressure from backing off while the pump isn't flowing, or between pulses of the fuel pump.

I just don't know what the damn thing is called and it's gone bad on my turbo LS. It's causing tuning problems * I think*. When I get on the throttle hard that check valve isn't holding the pressure steady on the rail, so Ii'm getting varying A/F readings from my wideband. Granted it's not a large fluctuation, but varies the A/F ratio about .3~.4....

Does anyone know where I can get one?

Thanks for any help guys.

~Steven


[Modified by Speed PHreak, 4:09 PM 8/20/2002]

 

its just the end piece of the fuel rail that sandwiches down on the banjo fitting. You should upgrade to a newer style oem fuel rail such as 94+ LS/GSR/ITR fuel rail. The newer rails have that white end fitting sitting vertically instead of horizontally...as seen here:

 

Thanx Katman, I found out what it is. It's called a pulsation damper by Honda and they want $40 for it.....

 

ah..
why not just get a new/used rail with that pulsating damper?
(heh, I feed that ladies my pulsating damper)

 

I have a question to add.....
Has anyone had any ill effects by removing the pulsation damper from the fuel rail? I'm more specifically interested in FI applications where the fuel system has been upgraded/replaced by larger injectors (440cc - 550cc), SS lines, and -an fittings. Did anyone notice a change in fuel pulsation with large increases in fuel volume per injection cycle? Please let me know what you experienced, I'd like to see if this is really an issue or not.

 

Nobody? well I guess I'll have to ask some engineering friends in fuel systems. Thanks anyways

 

I surfed over to some other forums in search of answers....I know the Rx-7's have problems with their pulsatin dampners so I did a search and came up with some good info.

http://www.rx7club.com/forum/showthr...threadid=29550

http://www.rx7club.com/forum/showthr...threadid=55958

Here is a good tib bit

"Now back to the pulsation damper (or dampner not sure). I read that the intention of this was for high cycling of the injectors. Every time you turn on the injector, the pressure in the fuel rail drops suddenly and when the injector closes, the flow stops suddenly and the pressure rises again. Cycling this way causes pulsation pressure waves in the fuel in the lines. This resonance then can be amplified just like a tuning fork vibrating. Given enough resonance, the energy in the wave can cause damage. If a low pressure resonance hits at the fuel injector when it opens, then you will be starving the engine of fuel and going lean. If the resonance continues too long, the high pressure waves can exceed pressure ratings of some components and connectors.

Mazda installed the Fuel Pulsation Damper to prevent these things. It is like a shock absorber for the fuel lines. Would you drive your car with just springs only and no shocks? One option for those concerned would be to place a fuel line extension from where the FPD mounts to a more easily accessible and less thermal place and mount the FPD on the end of that line. Although less efficient than the fuel rail mouning point, it should still serve the purpose. "

 

Steven,
Thanks for the info sources, it made for some good reading. I really think this is a mandatory part on any common rail fuel injection system. At work, there is alot of testing around this phenomenon. So I imagine it is not to be taken for granted. I only asked hoping to get some responses from people using/not using a damper on their set-ups. I was looking for real world results and observations. Thanks again.

 

I should note that the lower HP 1992-1995 Civics (DX, CX, and VX) don't have a pulsation dampener.

 

I would imagine it could also cause standing waves or resonance effects that could affect flow. Anyone who knows anything about fluid dynamics could probably explain it better.

Mike

PS. I am a firm believer in Honda engineering. If they thought there was a need for it thats good enough for me.


[Modified by 92sleepR, 3:50 AM 8/23/2002]

 

yep, but not all of it is performance oriented - i have heard the dampener was mainly to reduce noise???

anyone?

t..