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Consigli

OFFICIAL 280Z "Fuel Damper" thread!

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The FUEL DAMPER on my 1978 280Z is leaking and dripping gasoline. Aside from the obvious safety issues, it creates a pressure loss in the fuel system. The FUEL DAMPER sits directly above the fuel pump. Its purpose is to provide a smooth flow of fuel to the engine, so it is unwise to bypass it. This is Nissan part 22675-N4205 which is NLA and very hard to find. It was used in the 280Z, 280ZX, 810 & 200SX. The early unit has the adjusting bolt while the later unit does not. But both have the same part numbers and function the same. See the pictures. I have called all the usual vendors and have had no luck in finding one. Motorsport says they can’t even get it out of Japan anymore. The day may come when you may need one of these. If anyone has used a new aftermarket part with success please let us know what it is with the part number. And if you have a NOS one for sale, please let me know. Thank you. 

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post-29661-0-60791600-1448510917_thumb.j

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The newer designs attach right to the fuel rail,with an o-ring seal.  But you might try something like this - http://www.summitracing.com/parts/smp-fpd1/overview/  You need 5/16" barbs though, which is small.  Check the OEM applications to see if you can find hose size.  Or go to OReilly and see if they have one you can measure.  You would probably be fine mounting it in the engine bay also, closer to the injectors.

 

Here are some more options - http://www.summitracing.com/search/part-type/fuel-system-pulsation-dampers

 

I know someone who actually tuned their damper using the adjustment bolt.  He had someone turn the adjuster while he watched a pressure gauge.  When the needle stopped bouncing he was done.  But the later models probably have better damping materials or design so don't need tuning.

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That's probably as close as you'll get.  It's actually a Nissan design, for the 280ZX, 810 and 200SX.

 

Click on the FPD26 number in the description here - https://www.rockauto.com/catalog/raframecatalog.php?catalog=154&partnum=FPD26&a=www.google.com%2BSearch%2Bfor%2BSTANDARD%2BMOTOR%2BPRODUCTS%2BFPD26&blanktemplate=true

 

Cheaper too.

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I read a few things.  Always good to have a new reason to learn about an obscure part.

 

It's not really clear what the damper is actually for.  Some say it's actually there to damp the pump pulses from the original Bosch pump.  So if you have an aftermarket pump, maybe it's not necessary.  Some say that aftermarket FPR's have built-in damping ability.  No proof, just statements from nowhere.  Some say you'll have a poor idle if you don't have a damper.  Many say that the engineers wouldn't have put it there if it wasn't needed.
 
Seems like the best reason to damp might be to make parts last longer.  The hydraulic hammering from injectors opening and closing and stiff fuel lines might make parts wear faster.  Either the pump or the injectors.  Maybe it's actually there to protect the Bosch pump.
 
Just adding a few things to think about.  Good luck.

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Tried to add that damper to the basket in Rockauto and it says NLA.  No luck.  All of the old EFI  cars used an inline damper though.  VW, Toyota, BMW.

 

99% sure you can run without a damper while you're looking.  Cabin noise and, possibly, idle fluctuation, seem to be the major reasons to have one.

 

http://link.springer.com/article/10.1007%2Fs12239-012-0014-7

 

http://papers.sae.org/2000-01-1086/

 

http://papers.sae.org/971071/

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If you can't find one, I have a couple here (bosch and JECS). Shipping is going to be expensive.

You need to stop thinking datsun & JECS. Datsun simply copied Bosch, and I mean really copied.

There are plenty of Bosch units out there for BMW, Volvo, Jag, Renault, Citoren, Alfa etc and they will fit.

Try this link. Its the same as the 76 280Z.

https://www.rexbo.eu/bosch/pulsation-damper-fuel-supply-system-280161006?c=100269

Sucess.

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For about a year, I've been chasing a cold start problem. The first start of the day is always hard and takes a few tries and many seconds to catch. Afterwards it starts fine. I've attributed the problem to a pressure loss somewhere in the system. It now has all new fuel lines, injectors, cold start valve, fuel pressure regulator, thermotime switch & new factory fuel pump. And yet, the cold start problem persists. After doing some reading, I'm starting to think its the Fuel Damper that been causing the problem all along. I think its been leaking for a long time and causing the pressure loss in the system. I could smell the gas fumes in the air but didn't know where it was coming from. Now the leak has gotten worse and its actually dripping. So when I get it replaced, I'll know if it was causing the hard start problem all along. 

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I have just discovered the same issue with my Z, the leaky damper. And like you I have searched high and low with no luck. I'm running an aftermarket fuel pump so I will be removing my damper and will post results. I'm hopping to find that I don't really need it. According to the guys at MSA a few of their customers are running without one with no complaints.

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If you can't find one, I have a couple here (bosch and JECS). Shipping is going to be expensive.

You need to stop thinking datsun & JECS. Datsun simply copied Bosch, and I mean really copied.

There are plenty of Bosch units out there for BMW, Volvo, Jag, Renault, Citoren, Alfa etc and they will fit.

Try this link. Its the same as the 76 280Z.

https://www.rexbo.eu/bosch/pulsation-damper-fuel-supply-system-280161006?c=100269

Sucess.

Chas has the right idea. Part is available through Amazon.com and many others I'm sure.

http://www.amazon.com/Bosch-0280161006-Fuel-Pressure-Damper/dp/B000CF5W10

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Just looked at that one and will consider it after trying to run without one. I don't want to spend the money to find out it wont work, yet. And I don't want to replace it with a used one again. Thanks for the info zKars

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I've been running my 76 for 2 years without the damper (MSD fuel pump). My old damper leaked. I installed an inline fuel pressure sending unit/gauge and don't see any fuel pressure abnormal fluctuations during idle/driving. The idle is steady.

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From what I have read and heard from Mercedes fans here. The damper was used to help reduce pump noise. Once the pump has worn a bit, there is enough slip in the pump so if you removed the damper it would have little effect.

I must admit I don't have a new pump to confirm this theory.

 

These pumps are getting old and the internals are showing signs of wear. They have so much over capacity for the 280Z that you don't notice anything until they are almost completly worn out. Remember the original "Bosch" pump design was also used in Mercedes V8.

 

The Bosch version can be identified by the black terminal insulator section. The Hitachi has the light blue terminal insulator section.

They look very similar, but there are enough small differences the make most part non interchangable.

 

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I have found an aftermarket damper that might work perfect. But with the holidays, it going to be a few weeks before I can get it installed. If it works I'll post the part number. 

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Was contemplating removing mine this week. But I will wait, maybe, to hear results of the one you are installing. I'm not convinced yet that I need one while running an aftermarket fuel pump. I will give it some more thought. I may remove it and run the car just to answer a couple questions. Good price for the one you found though. Are you installing it anytime soon?

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The "Fuel Damper" turned out to be a very difficult part to find. Original Nissan ones are NLA and the supply of cross referenced after market parts has dried up. I spent many hours looking for a substitute and fortunately found one. Its been on my car for two weeks now and fits/works perfect. See my picture. It fixed the dangerous gasoline leak and pressure leak down between starts. No more gas smell in my garage and the car now starts instantaneously even after sitting for days! There is nothing that cross references this part to Japanese cars. Its for old BMW 3 & 5 series cars. But it works fine on my 280Z.

To do the job right, make sure you also get some good quality high pressure fuel injection hose and fuel injection clamps. You don't want gasoline leaks in this sensitive area with the hot exhaust just a few feet away! 

The part number is Bosch 0280161024.  Just do a Google search and plenty of buying options will come up. Good luck! 

Bosch Dampner.JPG

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Very cool info Mike. I still want to completely remove mine and see if there are any issues. I run an aftermarket fuel pump and want to know if we really need to run a damper.

Bob

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My fuel pump is a recently installed NOS one, because I wanted to keep everything original as much as possible. I wish I cut the old original Nissan dampner open to see if it was restricted before I pitched it, because the car seems to run better with the new Bosch dampner. 

Edited by Consigli

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Interesting that the BMW's they're on use the newer style fuel pumps.  Similar pump and engines overall to our Z's.  Must serve some useful purpose.

Looks like your local auto store might be able to get them, but you might have to ask for AC parts.

 

Fuel Damper Compressor Shaft.PNG

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I don't think your new damper solved the pressure drop. That would be the check valve in the new NOS pump.

The damper could slow the pressure drop if the check valve had a slow leak down rate. The damper does have capacity to compensate for pressure fluctuations and that would keep the pressure depending on the check valve leak.

 

I wonder what you would get if you ordered that A/C compressor shaft?

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I think that the assumption was that the gas leaking from the damper caused the pressure drop.  That would be a lot of gas though.

In general, pulsing and vibration cause wear and damage.  I wonder if the damper isn't also for durability of the other parts of the system.  The injectors and FPR and pump would all feel the shock of the pressure pulses from the injectors opening and closing.  Even the fuel hoses would pulse.  Might just be for wear and tear, in addition to noise.  Seems like pump noise could be handles with mounting insulation, hard to see that as the only reason.

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39 minutes ago, Zed Head said:

I think that the assumption was that the gas leaking from the damper caused the pressure drop.  That would be a lot of gas though.

The leak was causing gas to puddle underneath the car. 

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