[atoman]

I've started to see some 4th gen vans in the junkyard without this pulsation dampener on the fuel rail. Apparently it has been deleted from the rail by the factory design, and possibly moved somewhere else in the fuel system.

The fuel rail was re-designed to eliminate the need for this problematic component (the pressure test port was also eliminated) IIRC, the length at the end of the fuel rail was extended providing the volume needed for dampening the pressure pulses.

 

[atoman]

What year was it redesigned exactly?

How would I know exactly? probably around '04 when the refresh happened and the new plastic upper intake appeared on the motors..

 

[atoman]

IMHO, those fuel pulse dampers were a hasty solution to the problem of leaky fuel rails that goes back at least to mid 90's. The pulsation of liquid fuel caused by injector pulses sometimes caused resonance (hitting a "natural frequency") and caused catastrophic failures and fires...

 

[atoman]

FWIW, 3rd gen (96-00) used a single fuel line with pressure regulator on the pump..
Also, good luck finding a (traditional, in-line) fuel filter on the later 4th gen vans (it went the way of dinosaurs with '04? model year)

 

[atoman]

It's not a stupid hat,it's a fuel pressure damper,it has a function,and it is needed to dampen fuel pulses created by the injectors.

Must have been using special injectors on early 4th gen or the pulses loosen up dirt inside the in-line fuel filter..

How thick are the tube walls at the damper? can you tap the opening and put a bolt or cap nut in/on there? (with some thread sealer or epoxy)
The true ******* way of fixing it would be to put a hose clamp around the rail over the cap

 

[atoman]

I'm honored. I'm using a cable tie to hold the cap down. I used it to hold the cap in place while my JBWeld hardened, and saw no reason to remove it.

I'm glad you feel honored (vs offended)
What I had in mind was actually (a permanent 'emergency' repair) - such as splitting a length of rubber fuel hose lengthwise and clamping it over the damper opening with a stainless hose clamp..

Hope the new rail solves it for you.

 

[atoman]

Part number 4861498AB or 4861498AC for 2001 thru 2002 is available from Rockauto for $75 plus shipping.

Part number 4861498AD for 2003 thru 2007 is available from Rockauto for $113 plus shipping.

You can find a 5% off discount code here: RockAuto Introduction & Discount Code!

I did try first, and I had the worse result that some others had. I tried to bend the prongs back several times, and it must have to be just about perfect to hold. The injector o-ring was clearly big enough, since it squeezed into the cup, but it didn't hold. It took a bit of driving before it leaked though. No gas on the initial start-up. Since I've tried a few times and it doesn't seem to be working for me, I think I'll bite the bullet and get the fuel rail. The cheapest I can find it is $109 though, must've went up. http://www.factorymoparparts.com/04861498ad.html

Thank you georgef for the info!

Try rockauto.com as suggested above.. (search for the specific part# via their search box)

 

[atoman]

that diaphragm must be under the hammer
In most plumbing systems, fluid dynamics of inertial velocity are handled with a gas (mostly air) dampening (say that 3x fast).
Most likely the cap maintains an air bubble near the end of the fuel rail, the redesigned rails simply leave the cap out (are sealed).

 

[atoman]

IDK what the springs clip onto on the rail, but if you cut a strip of plastic or metal (from say a beer/soda can) just wide enough to fit under the clips on the stem on the rail and wrap it around the rail stem a few times to build up the thickness, then slide it up the stem with a pick or screwdriver - it should buy you enough thickness to 'retract' the clips and remove the cap intact. Some experimentation / several attempts may be needed (be patient, go slow).