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.
In executing my overly elaborate yearly maintenance routine, I followed Mike J's advice and took a good look at the fuel hoses in the engine bay. On my other mid 90s German car, the fuel hoses in the engine bay were bubbling and cracking, so I definitely wanted to take a look to make sure the 993 didn't have similar problems.
It's not exactly easy, but this was my experience in doing this for the first time.
Remove the air box and aux fan assembly as prerequisites.
From this fuel system page in the PET, I wanted to find parts 12, 14, and 23 in below diagram.
And then 6 and 1 from this page.
You'll see that not everything is visible with the intake on the engine, but with an inspection mirror and patience you can give all these lines a decent inspection. After doing this, I can be more confident they are not cracking, swelling, or bubbling yet.
#12. Locate this by following the line attached to the front (toward front of car) of the fuel filter.
#23. This connects to the fuel rail by the regulator on the left side of the engine. It's easy to find, but hard to see and photograph.
#14. This one is next to #12 on the right side of the car. The only way to see it is to move the two larger breather hoses and peek behind them.
#6. Easy. It's connected to the fuel rail on the right side of the engine and the fuel filter. You can't miss this one.
#1. You can't see the entire length of this because it's buried under a fair number of things. You can see a bit of it on the right side:
And even more on the left side:
Also, I swear the engine doesn't look this dirty in person.
Thanks Mike. With the handful of burned 964s and 993s this the past year, I thought it worth taking the time to have a look.
I took pics of the fuel hoses I pulled out of my Mercedes, but can't find them now. At 22 years and 175k miles, they were scary. Luckily, the hoses on my 993 at 19 years and 135k miles look new in comparison.
I have to think the hoses are of similar construction between the manufacturers. Perhaps the Porsche just stays a bit cooler in the engine compartment.
There is NOW WAY you can inspect the length of hose #1. It is buried way under everything, including the wiring harness and that support bar which connect the AC to the oil breather.
BTW, that very same wiring harness & support bar actually beginning to chaffe and wear through my hose #1. I had to buy a whole new fuel rail assembly.
FYI, the rubber fuel hose (1) that interconnects the fuel rails isn't actually the fuel hose.
Its a protective cover over the actual fuel line that is made of plastic. And that line is not crimped on; just simply a press fit onto the fuel rails.
I also replaced that clamp (11) because the rubber lining had dried up and broken away. There is an identical clamp next to it that also holds the wiring harness to the same bracket. I replaced that one as well; who needs a short circuit after it wears through the wiring harness insulation.
FYI, the rubber fuel hose (1) that interconnects the fuel rails isn't actually the fuel hose.
Its a protective cover over the actual fuel line that is made of plastic. And that line is not crimped on; just simply a press fit onto the fuel rails.
I also replaced that clamp (11) because the rubber lining had dried up and broken away. There is an identical clamp next to it that also holds the wiring harness to the same bracket. I replaced that one as well; who needs a short circuit after it wears through the wiring harness insulation.
Great insight Alex.
Makes me wonder:
1) Should that plastic line be longer-lasting than the rubber hoses?
2) Can you inspect the clamps while the intake is installed?
Makes me wonder:
1) Should that plastic line be longer-lasting than the rubber hoses?
2) Can you inspect the clamps while the intake is installed?
1) I bought an old fuel rail & line assembly because I needed just the rails for a project.
It wasn't till I started cutting off the rubber hose which acts as a protective jacket that I noticed a semi-rigid black plastic fuel line under it. That line is the one that feeds the fuel and handles the relatively low pressure.
I did take note of the markings on both the rubber and plastic lines.
Edited to add: to answer your question, the black semi-rigid plastic line appeared to be like new. I did some digging a while ago based on the manufacturer name and other markings on that line. It has to meet a DIM spec and along with that there is minimum bend radii, compatibility, etc. If the fuel rail line in my car ever deteriorates to the point of needing replacement, I'll simply rebuild it. I would worry more about the other rubber hoses (UV, heat, ozone, etc).
2) I don't know. I had everything off above the cooling shroud when I installed the new Beru ignition wires that I made up. Doing so gave me the chance to clean and inspect everything and that is when I noticed the clamps that needed replacing, This in a milder climate on a low mileage car.
Those two hose clamps attach to a metal bracket that is bolted down to the breather housing.
I'd be curious to know if Richard (the guy with 300,000 miles on his 993) has had to replace any fuel lines. I can't remember if it was mentioned in the Panorama article.
Timely topic with our coupes nearing age twenty. Does present day ethanol infused gasoline formulations give pause to fuel line type?
While maintaining the Frau's '79 Super Beetle convertible recently, a cursory fuel inspection was an eye opener. Out with the 1600cc 4-pot boxer for a comprehensive fuel line replacement. Did a double take when selecting a proper OE replacement fuel line. Present day North America gasoline formulations include extra strength... "ethanol", not widely present 20-25 years ago. The OE brand for Volkswagen, at least in the '70's was Cohline.
A more recent fuel line DIN spec will specifically include "ethanol" type fuels. FWIW for the '79 VW SB I use Cohline - 2240 combined with replica OE clamp type/yellow zinc.
I hear that ... time for an extinguisher..
Bought 2ea 5lbs extinguishers for the garage last summer. IIRC is was through Amazon; Amerex model B388 type Halotron-1 (5lbs) The coupe as a 2.5lbs Halotron-1
I'll be damned if I'll watch the coupe go up in flames .....
Hei from Norway!
My 993, 1994, has for a long time cheats, hiccup, to suffocates, and stops. I use mine 993 all season, winter whit spikes! Just after start, could engine, short drive. Sometimes after stop after short trip, stop engine because of refilling of gasoline, start and drive, then the same as described in this post. Not every day is this happend. Sporadically. Can this be a symptom of something wrong whit Engine fuel (lines)?
12-20-2015, 08:49 PM
Inspecting Engine Fuel Lines
