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tuurbo · Posted: Sat Mar 08, 2008 3:00 am Post subject: Twisted metal fuel lines

The fuel lines on the 931 near the fuel filter in the engine bay driver's side are twisted. It's about a 3/8" ID line and it appears to have been twisted when someone was tightening the fuel filter up. Now the twist seems to be enough to actually limit fuel flow. A buddy of mine who works on heavy rigs suggested this problem to me after looking at the lines - he's a sharp dude. Could he be correct? It seems to make sense on the face of it.

Anyway, I want to replace the fuel filter now but the connections are siezed and the twisted metal line is all wrong. Even if I hold the nuts with a wrench I fear it's going to twist the line further (in the opposite direction) or just become a mess. I don't want to give this to a mechanic because I don't trust their competence unless it's a Porsche dealer (who have the parts and history with the cars).

I'd like to snip the metal lines at both sides of the fuel filter and attach rubber/neoprine hose and fittings to the fuel lines and reattach the filter as per my buddy's suggestion.

Naturally this will create some funky fuel flow dynamics - but will that pose a problem or have we got so much pressure with that fuel pump that the change in flow won't be a problem?

Thanks for any ideas.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

9magazine · Posted: Sat Mar 08, 2008 3:12 am Post subject:

At time point trying it isn't going to hurt anything! If it doesn't work you will be replacing the metal lines anyways to make it correct.

Brian
9magazine.com

1980 931
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Brian
9magazine.com
'80 931 5spd - 4bolt wheel

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

tuurbo, i have a couple of 931 rolling chassis that still have the metal fuel lines intact. If you end up breaking anything or want to replace your twisted lines, I can get you a replacement.
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erstwhile owner of just about every 924 variant ever made

Rasta Monsta · Joined: 12 Jul 2006 Posts: 11733 Location: PacNW

Obstructions are tricky, because idle system pressure may not be effected, but flow volume could be. . .tough to test under load!

I say swap 'em.
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Toofah King Bad

WeiBe (1987 924S 2.5t) - 931 S3

Smoothie · Posted: Sat Mar 08, 2008 3:31 am Post subject:

Due to the high pressure on that line (close to 100psi), I wouldn't be comfortable at all with rubber lines added there.
The fuel filter connections are normally extra tough to loosen. I usually have to use 2 pair of Visegrips. Be aware that Visegrips, attached too tight, will deform the connectors, but you can put that to good use by attaching, releasing, repositioning, attaching, releasing, etc. around the fitting to help break loose any corrosion that's on the threads. Try that along with an application of WD-40 or whatever.. -And use 2 Visegrips or other wrenches together.
One other thing - the adapter fittings that were factory-attached to the fuel filter are more-or-less permanently attached with epoxy or some type of extra tough threadlocker, so don't even try to loosen the adapters from the filters while on the car. Detach between the adapters and the line-attached fittings (<-usually green-colored).
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"..it's made in Germany. You know the Germans always make good stuff."

'82 924T, US version, dark green metallic, 5 speed Audi 016G gearbox

tuurbo · Posted: Sat Mar 08, 2008 4:23 am Post subject:

Right so if I go the rubber/neoprine route I'll probably be blowing gas all over anyway. Smoothie when you mention the epoxied filter connectors it's all making sense now - someone working there has maybe tried to move that piece at the filter.

The twisted lines...I was thinking too from boating that the way they're twisted right now I'm probably looking at something at least like cavitation in the lines - yeah they should be replaced.

Yes Ideola I'd be interested in those lines when things go wrong. Thanks very much. How can this be done - I'm sometimes out Detroit way... Are they the very long ones stretching around back of the engine bay to the fuel distributor?

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Let me know exactly which parts you need. I'm planning to start stripping the one chassis within the next month. Once I get the lines off of the car we'll have to figure out how to get it to you. Shipping could definitely be a challenge...
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erstwhile owner of just about every 924 variant ever made

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Hey tuurbo, I'm going to be working on my two 931 rolling chassis today. Do you still want those fuel lines?
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erstwhile owner of just about every 924 variant ever made

tuurbo · Posted: Sun Mar 16, 2008 1:53 pm Post subject:

Yes absolutely! Thanks! Any chance on a WUR for a 1980 too?
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

tuurbo · Posted: Sun Mar 16, 2008 4:17 pm Post subject:

Yeah I'm close enough to Detroit when I'm traveling with my wife. We could easily be in that area in a week or ten days I think.

I'll take the fuel line picture tomorrow. I looked at it again today, man, is it ever bad. You'll see tomorrow but it's the line from the filter back about 8" (from memory) then along behind the heater fan input over to the passenger side and down to the CIS. It's twisted right at the filter - you'll see.

When I look at the twisting I just think, man, whoever working on this did not treat it like it was their own car.

Yeah I can clean up whatever WUR you have for the Series 1. I'd clean the filter thing and clean the connections but I'd probably try it out before rebuilding. Unless it's easy.

When they rebuild the WUR, how do they get a bimetallic spring? They probably don't have those at Home Depot I'm guessing.

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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

OK, so it sounds like the pieces you need are the ones that are completely contained in the engine bay. NP. I'll get to work on it this week and dig out a WUR. Re: the WUR, you will have to consider it good only as a core. Most guys these days have been using Special-T to have them rebuilt.
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erstwhile owner of just about every 924 variant ever made

tuurbo · Posted: Sun Mar 16, 2008 11:51 pm Post subject:

Wow ok this isn't gonna be easy - I have to make sure that mechanic didn't replace my WUR with another WUR I gave him to consider as a spare. I guess I'll be over there on Monday making inquiries. They need the exact one and I'm unsure whether mine was an early or late 1980 924T.

I figured those WURs were gonna be expensive.
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

tuurbo · Posted: Mon Mar 17, 2008 8:37 am Post subject:

Hey ok the shots below are of the line from the filter back toward the driver.

That's gotta be hurting the flow yes? I look at it and it just slays me that happened. Looks like he was trying to get it off, not on, when he twisted it (leftie loosie righty tighty).
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1980 924 turbo, MSD, Meth. Inj, otherwise stock.

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

Yeah, that's pretty ugly. Should be no problem to get you a good set of replacements from one of my donor cars.

Regarding the WUR, I'm not aware of the different part numbers for the 1980. Do you know which part number you need??? What could possibly have changed with respect to the WUR in mid-year? In any event, I've got a few extras, I'll get the check the part numbers.

My comment re: the WUR being a core was simply a disclaimer that I cannot / will not warranty it for proper functioning. As such, it may work just fine they were working when removed), but if I sell you one, you should consider it as an item that needs to be rebuilt. I think Special-T offers core exchange, so the price for rebuilt might be less than the online price. I did a cursory search on their site for such info, but didn't come across it. Might be worth a phone call.

Stay tuned.
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erstwhile owner of just about every 924 variant ever made