Should I replace ALL fuel lines on 86 Carrera?

[zippy_gg]

I am replacing for sure the fuel lines feeding the fuel injectors on my 86 Carrera but I am wondering about the fuel lines in the tunnel and the 2 lines that connect to them and to the fuel filter. Are these 4 lines at risk and should they be replaced as well?
If so now would be a good time as I have the steering rack out and the engine/transmission out.
Advice, please?

[chrisbruck]

I 'd replace all that you can get to easily. The PO on mine replaced the pressurized engine bay ones but I have one that connects to the expansion tank that likes to drip if you overfill it.

[wildcat077]

The lines in the tunnel are hard plastic ... unless the connection fittings show some damage i wouldn't bother.
Give Len Cummings ( Boxster GT )a call,he made some really nice conversion lines for my 3.6

Cheers
Phil

[neilschelly]

I'll second the recommendation to talk to Len about getting new hoses for the intake manifold. That'll get all the hoses on the engine side of the fuel filter replaced.
-N

[javadog]

I'd replace them all, since you have both ends of the tunnel accessible. People have seen problems with the lines through the tunnel occasionally and they aren't all that expensive.

Whatever you do, I'd change the lines in the engine compartment, especially the one that always leaks.

JR

[gjmascoli]

At the risk of highjacking the thread, can all the engine compartment lines be sourced from our host? I seem to recall some of the lines for my '76 aren't available.


From where can I source a complete set of engine. Compartment fuel lines?

[zippy_gg]

In regards to the cost, both tunnel lines and the lines in the engine compartment add up to about $450, plus tax and shipping from our host.
That does not include the lines on top of the engine that Len can provide for around $350 or so...
So that is over $800 on fuel lines only, hence my question about replacing what is necessary (such as the lines on the engine ).
My thought is that everything rubber should be replaced, but I wanted to check with the wisdom on the forum first.

[LEAKYSEALS951]

Your car is younger, but I just replaced all lines on my 1978. Here's a pic of one of my main lines that was not exposed to the heat of the engine compartment.

[zippy_gg]

Leaky, I read your thread and that what caused me to question whether or not to replace the tunnel lines, then I found there were made of different material.
It looks like I'll be replacing the 4 lines in the engine compartment at a minimum.
I am in the process of removing the tank so I should be able to inspect the end of the tunnel lines at the front.

[steely]

I did the engine on my 87 five years ago when I bought it. I did the tunnel last year.
I regret not having done the tunnel when I had the rack out (when I was doing the suspension 3 years ago).

Engine lines are more prone to heat or course. The transition in front of the tunnel can leak but is not as susceptible to fire. After I did the tunnel lines, all traces of fumes disappeared.

Certainly finances played a big role. If you are doing the FE and can swing it, do the fronts/tunnel too or as soon as you can.

[LOVEHZ]

Is there more than one type of fuel line from the fuel filter to the injector rails? ie an upgraded fuel line?

[Spenny_b]

Perhaps not so relevant to the OP (ie with plastic lines), but to anyone else who has metal lines like I had, I found this quite sobering when comparing the lines to the general condition of the rest of my car (which is generally excellent); compared to other 964's I've seen photos of over here in the UK, where various parts of the underside structure are starting to rot out, mine has none of that, and yet still the lines are well past their best and now replaced with -6AN hosing, new pumps, filters, fittings etc.....(car is a 1993 964 Turbo, with approx 82k miles) --->

[Tidybuoy]

The lines in the tunnel are pretty protected - there's actually a tunnel inside the tunnel just for the fuel lines. Those lines are polymide and will last a very long time (it's the early cars that really need tunnel lines replaced).

The lines in front that go from the tank to the pump and tunnel should probably be replaced. These are rubber and are somewhat exposed to the elements and definitely wear out. Same with the engine compartment lines.

[scooterp7]

I vote for replacing all the lines. On my 87 they all needed replacement, the worse being the "J" shaped hose on the back of the engine. The front lines weren't terrible but the factory lines are not ethanol rated. Mine came from Len aka Baxter GT. Do not forget to replace the four grommets where the lines enter and exit the body.

Scott

[dap930]

The best argument for using replacement fuel line from Len at autosports.com is that they are made with ethanol compatible hose. Older cars are not equipped with this hose. The replacements from Porsche may not be rated for ethanol use.

[gregwils]

I replaced all of mine from the tank to the fuel injectors, including the tunnel. I had the motor out and the front suspension out, so it was relatively easy. I used new OEM lines for the tunnel. I reused the metal lines in the engine compartment along with german Cohline hose and high quality Oetiker clamps to make my own engine compartment hoses. The photos of what Len produces appear to be high quality.

PS - There is a large vacuum hose fitting coming off the rear tunnel....while you're in there.

[HaroldMHedge]

Gregwils,

I have my engine out right now for oil leaks and will be address my fuel lines while in there. I see that you have used Oetiker clamps instead of the factory crimp-on hose ferrules.

How has this held up over the years?

Edit:
If anyone else has used Oetiker clamps instead of the factory crimp-on hose ferrules, I would also like to hear from you about your experience using them.

Harold

[Knockdown]

I replaced all of the rubber fuel lines from the tank to the tunnel and from the tunnel to the motor using Oetiker clamps about 3 years ago, no issues.

[RogueEngineer]

I faced the same dilemma ('85 Carrera).

I pulled the lines out of the tunnel but aside from the ends being dirty, the synthetic (polyamide?) lines were in perfect condition. Unless you suspect they've been damage from a foreign object, I wouldn't bother replacing them.

Cut rubber/steel swage on the fuel tank side and use fuel injection hose clamps over the now exposed barbed end.

[burgermeister]

I replaced all the soft rubber bits in the engine compartment as well as from the fuel pump to the tunnel with SAE Fuel Injection hose from my FLAPS. Left the hard plastic lines in place. I cut the swage off with a dremel and used hose sized to fit the barbed end. FLAPS did not carry metric, the SAE sizes were close enough to work. Used FI hose clamps also supplied by FLAPS to secure the connection. I did double up clamps where space permitted. Total cost was <100. These have been in trouble free service for 8 or 9 years, 50K miles, lots and lots of track time.

With one exception. I did not use FI line for the tank to pump connection (gravity pressure) - just standard SAE rated low pressure fuel line. It showed significant cracking after 2 years. I suspect alcohol in the fuel settling out and concentrating at this low spot over winter storage. Replaced it with FI line, and no issues since.