# Mystery component



## kn1ghtride (Dec 1, 2009)

Hey guys and girls,

I have a 1994 D21 XE and it won't start. It seems no fuel is going through so I assumed it was a faulty fuel pump. Upon attemting a replacement, I discovered a mystery component that looks like a fuel filter, but seems more like a valve. This device has a snap in near the fuel tank with an inlet and outlet labeled "Tank" and "Eng". I have checked my shop manuals and don't see anything that looks like this part and I checked most of the autoparts stores and nobody stocks or can ID the part. I pulled it off the truck and realised it has a hole in it (though the previous owner taped the hole with electrical tape) and that a hose was disconnected. Has anyone seen this part and if so, what is it and where can I get a replacement?

Thanks-
Joe


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## kn1ghtride (Dec 1, 2009)




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## kn1ghtride (Dec 1, 2009)

*Mystery pic*

That's a picture of the part in question.


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## Faja (Aug 31, 2009)

kn1ghtride said:


> That's a picture of the part in question.


If your truck doesn't have another fuel filter then I'd guess that's it??


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## kn1ghtride (Dec 1, 2009)

Since the fuel filter is located near the engine, this is a mystery. Since it was broken anyway, I pulled off the top and there is a grommet, a white nylon part (strainer) and a spring.


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## kn1ghtride (Dec 1, 2009)

pictures don't seem to appear!


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## Faja (Aug 31, 2009)

I think it's called a "fuel damper"


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## zanegrey (Dec 5, 2005)

is it inline with the fuel or the air vent for the fuel tank ??


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## SPEEDO (Jun 9, 2003)

I'll bet its a check valve....


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## coolen (Jul 17, 2008)

zanegrey said:


> is it inline with the fuel or the air vent for the fuel tank ??


The mystery part in question, goes in the vent line by the tank.


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## SPEEDO (Jun 9, 2003)

sounds like a check valve....


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## CMax03 (Jan 17, 2009)

Previous owners doing..... non oem part..... but should be a check valve!


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## kn1ghtride (Dec 1, 2009)

It is a genuine Nissan part- you can see the nissan logo


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## Faja (Aug 31, 2009)

check and see if you can find a manufacturer's number on it, then try googling it if there is one.


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## kn1ghtride (Dec 1, 2009)

*Mystery part*



Faja said:


> check and see if you can find a manufacturer's number on it, then try googling it if there is one.


I checked the part from top to bottom and the only numbers on it are 2 3 1 .


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## Faja (Aug 31, 2009)

kn1ghtride said:


> I checked the part from top to bottom and the only numbers on it are 2 3 1 .


Ok, I'll give this one more shot - after doing some searching I came across one other possibility - it might be a "vacuum cut valve bypass valve" that is hookup up from the vent line on the gas tank to the EVAP canister.


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## kn1ghtride (Dec 1, 2009)

Faja said:


> Ok, I'll give this one more shot - after doing some searching I came across one other possibility - it might be a "vacuum cut valve bypass valve" that is hookup up from the vent line on the gas tank to the EVAP canister.


I'll give that a check also. This device was on the passenger side, rear of the 1994 D21 extended cab with a 6 Cylinder engine. It was connected with 1 squeeze clamp and the other end was just hanging there so I am guessing one clamp fell off. So far none of the possibilities look the same as that part that came off the truck. It was also snap fit into a hole under the bed near the fuel pump, probably 6-12" away. I might break the other end open to see what is inside. Thanks everyone for the feedback so far... We will figure this out yet.


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## LucidOne1 (Mar 26, 2009)

Just checked the FSM for that year and it says it's a fuel check valve. PM me your email and I'll send over the section if you want it


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## CMax03 (Jan 17, 2009)

Maybe the parts guys at a local dealer would know....Most of the Nissan check valveare inline but not like that one....Or it's off another Nissan but not a HB


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## kn1ghtride (Dec 1, 2009)

CMax03 said:


> Maybe the parts guys at a local dealer would know....Most of the Nissan check valveare inline but not like that one....Or it's off another Nissan but not a HB


Definitely a hardbody (94 Extended cab 6 cylinder 4WD).
I'll try to find a local dealer- I live in the boonies!!!


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## Faja (Aug 31, 2009)

kn1ghtride said:


> Definitely a hardbody (94 Extended cab 6 cylinder 4WD).
> I'll try to find a local dealer- I live in the boonies!!!


could be a "rollover check valve" as in this thread. Check out one of the last pics close to the end - just like yours!!

http://images.google.ca/imgres?imgu...prev=/images?q=nissan+check+valve&gbv=2&hl=en


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