When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
On a bit of an inspection this morning, spotted this...
That's the fuel pipes at the rear. The sad looking rubber pipe is bending around the front of the rear subframe.
Apart from it obviously needs replaced, the whole thing looks unlikely. The rubber pipe runs all round the top of the wheelarch and ends up at a similar looking fitting at the top-rear of the wheel arch. There are lots of cable ties involved.
Is this correct or some sort of bodge? It certainly doesn't seem a good idea to have that sharp bend around the subframe.
Any pointers as to how it should be done are appreciated. And... if that rubber hose is right, does anybody know what bore size it is so I can order some new?
Porsche do not use Jubilee clips on fuel lines AFAIK.
There's nothing about it to suggest it being factory. The question being what should be there. If it is a rubber fuel pipe then it's a hell of a tight bend.
Those fittings typically have a barbed connection about 1 inch lon and I would think that DIY bodge is kinked over the end of the barb.
If the routing is stock for that model year then one imagines Porsche would deploy a pre-formed hose able to make a tighter bend radius whereas a DIY amateur would probably use a straight hose of some kind with a larger bending radius than space available dictates.
Unfortunately I am not familiar with the layout on your model not that I would expect it to be much different to mine. Is that on the fuel feed line or the fuel return line? Either way running like that is not realistic and you need to rain the system and get the detrius out. If that section is like that what condition is the rest of the fuel plumbing system like? No idea what size that hose is and doubtless someone will know but you can cut the hose and measure it. I understand all fuel hoses are based on imperial sizes like 5/16th inch or whatever but I could be wrong on that one.
I happened to be under my 86.5 and snapped these pics. (I'm not positive the angle of your pic, but one of these should be it) There are a couple of tight 90 degree turns.
Anyway there are nothing but metal lines in that area on my car, and certainly nothing like what you have. I suspect the previous owner had a rubber line fail and he took it off, removed the factory metal-to-rubber "crimp" clamp and slid some hose and clamp on the remaining barbed hose connection.
And yes, 3/8th inch high pressure fuel hose will work, and should be less likely to kink. Use a fuel injection clamp (the solid metal kind, not the universal clamp you have now.
Not sure what's going on. It's clearly been replaced at some point - hard to know what was there before. The rubber pipe is properly cracked and degraded.
I've ordered some more injection hose (it's the pipe that comes from the pump) and will figure something a bit more sensible out.
They are not called "Imperial" units because they were made in China!
If the original spec was metric ze Germans would have sized it at 10mm not 9.5mm! Same for ac system fittings by the way. I like the US system of referring to them as a number of 1/16ths- thus 3/8th is 6AN.
They are not called "Imperial" units because they were made in China!
If the original spec was metric ze Germans would have sized it at 10mm not 9.5mm! Same for ac system fittings by the way. I like the US system of referring to them as a number of 1/16ths- thus 3/8th is 6AN.
Good point!
A lot of the vendors here describe it as "10mm Injection hose" and then in the spec says "9.5mm ID". Sigh....
Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!
A lot of the vendors here describe it as "10mm Injection hose" and then in the spec says "9.5mm ID". Sigh....
They would do in the UK- 10mm hose indeed has an ID of 9.5mm which is exactly 3/8th of an inch- they are one and the same thing- when it comes to hose sizes or as best I could fathom out.
On the other hand if you really want to get confused when it comes to tubing systems 9mm tube has an OD of - you guessed it- 9.5mm. 3/8th tube has an OD of- 9.5mm! Needless to say the fittings and the tubing size are not one and the same thing.
In the oil industry we had to be very careful when it came to impulse tubing systems [the kind of stuff we use to carry the process conditions from piping into instrumentation]- metric sizes and imperial sizes were very similar and the threaded connections looked more or less identical but they were not- one having a thread angle of 60 degrees and the other 55 degrees- try eyeballing the difference between those two! Get a mix of components and it could potentially be disastrous.
I'm more than happy to run new (kunifer) pipes up and down the car. In fact, it's probably looking like a very good idea.
The thing I struggle with is figuring out what the correct connectors need to be on the ends. Anybody knows, or any advice on working it out, much appreciated.
EDIT:
From my limited research it looks like 10mm compression to AN6 (possibly AN8) fittings are the answer. Some measuring / sanity checking on the car next.
Last edited by thepurpleblob; 06-20-2023 at 04:18 PM.
Porsche do not use Jubilee clips on fuel lines AFAIK.
They do now 8>(
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
06-17-2023, 08:34 AM
Very iffy fuel pipe
George Layton March 2014