Fuel pump....again??

[giuliot60]

RR just mentioned that the pump intake connection from the tank is 12mm, not 8mm. I guess we should be "measuring twice, buying once"

And he also found this part: BECK/ARNLEY Part # 0430899

[4uall]

I thought based on this post http://forum.fiatspider.com/f08/viewtop ... ES#p116434 we were looking at the gas delivery system line 5/16 or 8mm

[giuliot60]

That's what the professor says. And he's a pretty good authority.

My understanding is that from the fuel pump forward it's 8mm, but between tank and pump it's 12mm. I will have to go under the car and verify.

[4uall]

crap I may have to get more/different line Thanks for the clarification

[giuliot60]

Here's his explanation Jay.

"Giulio,

A basic point is the both ends of the strainer must fit a hose with a 12mm inner diameter (ID). Filters with barbs that are 7-8mm in outer diameter (OD) don't fit a 12mm hose. The pump has a 7mm output barb but a 12mm input barb. Many people assume the hose is 7mm all the way to the tank nipple. It is not.

The reason is that fuel is flowing from the tank under a gravity pressure head and there are only a few inches of height difference between the bottom of the tank and the pump inlet. So pressure behind the flow is slight and resistance to flow must be minimal. By design, the original Bosch pump does provide much suction. It is a pusher, not a puller.

So, we are talking about a big, uncommon fuel hose size, a size that most parts stores don't even carry. The slightly larger 1/2" size (12.7mm) is common enough in marine and farm equipment applications but 1/2" strainers tend to be large, too large is fit over the rear axle, and most are designed for vertical placement, not horizontal or "in line". I think you can find universal glass filter kits that come with multiple end fittings that may include a 1/2" option.

VW had a gravity flow to an external pump in some Vanagons. It used a secondary filter that looked like a translucent white plastic cube. Some years it came with a 12mm barb on one end and a 7mm barb on the other. Some years it came with 12mm on both ends. Somer years it was a real filter, some years it may have been a strainer. You might poke around Vanagon parts listings. I found this one on Rock Auto,
BECK/ARNLEY Part # 0430899

I've added the NAPA strainer to an on-line order from them. We'll see what they say. It is still a good part number in their system.

Richard"

[ga.spyder]

I checked with NAPA this morning...not available.I ordered a Wix ,but I have no idea on size.Since it is for big rigs,it may be bigger than the fuel tank!!

[Europa]

I do believe it's 12mm ID from tank to pump and 8mm ID from pump to rail on injected cars (on unmolested Spiders). The injector hoses are 7.5mm ID. I changed my hoses a couple of years back, but this is what I recall.

[4uall]

found this old post

I just did mine & got a nice gas shower. you'll need a piece of 7/16 from the tank to pump. I also ordered the correct metric stuff for the fuel rail, 5/16 f.i. hose on the rest.

good enough for me, going to pick up some 12mm

[giuliot60]

found this old post

I just did mine & got a nice gas shower. you'll need a piece of 7/16 from the tank to pump. I also ordered the correct metric stuff for the fuel rail, 5/16 f.i. hose on the rest.

good enough for me, going to pick up some 12mm

Cool. Let us know what and where you get it from. Do you also have the link to the post htchevyii's quote came from?

Thanks.

[ga.spyder]

I got the strainer/filter from Oreilly's.Nice small metal cased unit.Wix #33270,sells for around $10.Cheap insurance! Thanks for researching and finding that,Jay.I will install it this weekend,along with my brand new Bosch fuel pump

[Europa]

Craig, what's the inlet/outlet size on the Wix?

[4uall]

found this old post

I just did mine & got a nice gas shower. you'll need a piece of 7/16 from the tank to pump. I also ordered the correct metric stuff for the fuel rail, 5/16 f.i. hose on the rest.

good enough for me, going to pick up some 12mm

Cool. Let us know what and where you get it from. Do you also have the link to the post htchevyii's quote came from?

Thanks.

here you go http://wwwe.fiatspider.com/f08/viewtopi ... wer#p27111

[ga.spyder]

Abey,the inlet and outlet are 5/16''.That should work fine for me,as I used 3/8'' f.i. hose from the tank to the pump.

[giuliot60]

3/8"? And that fit over the tank outlet and pump inlet?

FI rated hose is not necessary because there isn't any pressure behind the pump, but it certainly won't hurt.

Let us know how it goes.

Good luck!

[4uall]

so confused my head hurts