Posted: Sun Dec 21, 2008 11:34 am
My only helpful info on this. You can get excellent Braided, German, High Pressure Fuel Hose from any Porsche dealership.
Tech and Community Help For Air-Cooled VWs
http://www.itinerant-air-cooled.com/
http://www.itinerant-air-cooled.com/viewtopic.php?f=50&t=5388
The line to the filter is the smaller, the outlet to the pump is the big one, and then we're back to smaller on down. Why do they do this? Well, the larger diameter from the filter to the pump is to prevent the pump from cavitating at start-up. The only place in the entire fuel loop that could draw down to a negative pressure is between the resistance of the filter media and the inlet to the pump. So I think it is serving as an "accumulator".Lanval wrote:I assumed that there should be 12mm line coming from the tank to the filter (as is currently the case with my van), but the filter CLEARLY is NOT meant for that size line.
On the intake side of the filter (side opposite the indicated direction of the flow arrow) the intake is too small for a 12mm line. The output side, however, fits 12mm perfectly.
So is this correct: 7mm tank to filter, 12mm filter to pump, 7mm from pump onwards?
If so, will it matter if the 7mm hose I use is the BMW stuff that I got from Van Cafe?
Well, I apologize if I am giving you addled advice, but I have my Vanagon Bentley on my desk here, and they have lousy photographs and extremely terse copy. Under the Digifant, the prefilter is NOT to be used with pumps that have their own filter already. So put that in your pipe and smoke it. We have to use our wits, that's all there is to it.Lanval wrote:My van has an 11mm outlet from the tank to low pressure filter, and the filter is 11mm on both sides. This is an OEM style in-line filter.
VW parts confirmed that this 11mm in/out square filter was visible on his screen, but there was no part # associated with it, and when the parts guy clicked on the picture of the filter, the system returned a "NLA" message.
1)Somehow find a NOS original filter
2) Get a new gas tank with a 7mm output
3) Replace the current filter with an adjustable aftermarket filter
add the inline filter after the pump, and simply delete the pre-pump filter.
I went with #3, and I'm going to add the post-pump inline filter (since those gas lines should be changed anyway, now's the time to do it.).
OK, so my acuumulator guess may have had some traction. . . .Lanval wrote:The only answer for that change from the earlier set-up that I've seen is a rumor of a VW TSB that argued Vanagons should have the pre-filter removed, and run a 12mm line directly to the pump, with the canister filter on the post pump side. The claim made is that this alleviated a pressure/supply problem to the pump, caused by the filter.
Over on the Samba, Tencentlife worked out the fuel supply numbers to verify that (on the WBX at least) the fuel supply was at least 3x what the engine needed at any given point, necessitating the flowback system.
BTW, I'm planning on seeing you next year ~ pencil me in! No crappy economy or evil grad school people can usurp that pleasure!
Kris,airkooledchris wrote:
they look to be small and round in the picture, but all of the ones ive seen have always been those square white plastic ones, usually made in India like this:
1986 and up:
[albumimg]2349[/albumimg]
the 86 and up Vanagons shows two filters in one part of the diagram and just the post-pump one in another.
The number 7 on the graph above shows this part number:
1h0 201 511
This is for that metal canister style filter you see after the pump
You can see here where they reference the proper pre-pump filter being NLA, but it looks like the one you can still buy if you look for the 80-85 pre-filter (133133511)
It's funny that they show the "replacement" as a 390mm section of FI hose (N-020-300-1)
I unfortunately cannot comment on the size of the line coming into the filter and then out of, in terms of how that varies from model to model, but I thought the late baywindow fuel filters worked on the aircooled vanagon models (its the same part number.)
on the PLUS side you can take it back under warranty if it fails anytime soon. I don't know what the negatives would be, so long as its correct for your vehicle.Lanval wrote:Any problems with getting a Bosch unit from CarQuest/NAPA?
. . . never again post such long link tags that it stretches the window.Lanval wrote:I'm actually planning to . . .
Those that write the software that underlies the forum should address this shortcoming.Amskeptic wrote:. . . never again post such long link tags that it stretches the window.Lanval wrote:I'm actually planning to . . .