1972 911 Targa

[lostinamerica]

Inherited a 1972 911T targa that has been sitting for 10 years. I am in the process of trying to get it started after sitting for so long. I have removed the fuel and the gas tank to send out to be cleaned and coated. I want to replace all the fuel lines from the tank to the motor. My question is, am I correct in assuming that I need to access the fuel lines from inside the car? And to do so I need to remove the seats and carpet and hopefully they are located along the "hump" between the seats. I am new to fuel system but have rebuilt & restored a few Porsches in the past. Any advice would be greatly appreciated. Thanks

[kugelfischer]

While there are fuel lines running through the tunnel, it's highly unlikely that these need to be replaced as they are hard lines and should be intact. You should be fine with doing only the soft lines which are outside of the tunnel.

[David E. Clark]

You will need to clean out the hard lines. A quick way to do this is to blow compressed air through the lines. A more thorough way to do it is to run a small brass pipe snake through the lines. If gas sat in those lines for 10 years, varnishing might be a real problem.

[47silver]

We are replacing ours and I do not think you can do it without pulling the engine transmission.

[lostinamerica]

Thanks to those of you who responded. My problem is, in order to remove the gas tank I had to cut the two lines leaving the tank. Is it possible that those two lines have a connection were I could replace a section of the line, somewhere down the tunnel as to make it a bit easier to replace without removing the transmission? Also are there any good diagrams and/or photos that show the fuel lines as to how they run down the tunnel? As always I appreciated any and all advice.

[rmbarros71911T]

You didn't say where you cut the fuel lines between the tank and tunnel but I'll assume you cut a hard line vrs a soft (rubber) line. The hard line that runs through the tunnel is clipped in several locations so it's not just a matter of pulling it out from one end or the other. You are going to need to get access to to clipped points inside the tunnel by removing the carpet cover, the shifter boot and maybe the shifter, the handbrake boot and maybe the handbrake linkage. If you don't actually have to remove it, I wouldn't worry so much about varnish in the fuel line. You can always run a lot of compressed carb cleaner thought it to clean the varnish out. As long as it is not full of gunk or blocked you will be ok with carb cleaner and compressed air. At the end of the day if you decide to remove it you may be able to do if from the front with the tank removed. I haven't done it that way but with sufficient swear words it may work.

Rich

[Porboynz]

There are no joins in the tunnel for the 2 x fuel lines. As long as you have approx. 1/2 inch of solid lines exiting the bulkhead from the tunnel then you have enough to attach a brass fitting with suitable sized olive compression fitting. Those in tunnel lines are a pita to replace, but it can be done, just, without removing the engine/trans.

[lostinamerica]

I appreciate everyone's input. I will start my investigating this weekend. Does anyone know of where I could find a diagram of the fuel lines thru the tunnel?
Thanks

[Sunroof]

A whole bunch of stuff shares that tunnel (brake, throttle cables for example) so removing a hard fuel line serves no purpose unless you know its blocked, bent or crushed. Rich is correct in recommending you use a solvent and compressed air to clean so why not try that first?

A few weeks ago another thread showed up about a car (1973) sitting for 8 years and the stuggle to get the fuel issues taken care of. In this case it was the CIS. After eight years they flushed the fuel system and replaced hoses that took care of any varnishing or issues in the lines.

Personnally, your going a bit overboard here by assuming the fuel lines in the tunnel are easily accessible and easy to replace. As suggested you will save time, money and aggrevation by just cleaning them out and then adding the new fuel lines from the tank to the forward hard line and the rear of the hard line to the pump. Give that a try first. This might shorten your list of things to before cranking her over.

Bob

[kodioneill]

The search function is your friend.

[David E. Clark]

It is very, very unlikely that the hard lines through the tunnel need to be replaced. The only way I would replace the lines is if you have some identifiable reason to worry, for example compressed air will not go through the line because of some obstruction or you suspect that the lines have rusted through. Otherwise, I would cap off one end of each line and spray some solvent (like B-12 chemtool) into lines then cap off the other end and let it sit overnight. If you lift one end of the car to get a slight incline you will be able to fill the lines with solvent. Remove the end caps the next day, blow out the lines with compressed air, replace all the flexible lines and clamps and move on to your next issue.

I used a tiny brass pipe-snake hooked to a power drill on the lines in my car but that's probably overkill.

[BoxsterGT]

I have a bit of experience with fuel systems and will add my 2 cent opinion.

First, let me say that "lines" are usually rigid while "hoses" are usually soft and flexible as with rubber hoses.

A 72 model will have steel lines through the tunnel. Unless blocked solid with rust it would be a mistake to pull these tunnel lines. If you pulled them, what would you use to replace them?

With later models its another story, but with a 72 a good flush with White Vinegar will clean out any loose rust in the lines.

I think what you have cut to remove the fuel tank are the rubber hoses, and they can be easily replaced. Do you have carbs or MFI? Either way, the pressures are not high enough to be a problem. Use good factory type hose clamps like Norma or Oetiker and the good E-85 resistant fuel hose and you will be just fine.

Hope this helps.

Len

[47silver]

len
would you consider the tunnel brake line the same as gas lines? clean it with brake cleaner or should we replace the brake line in the tunnel?
gary

[BoxsterGT]

The tunnel brake lines are steel also. Most of the older ones are painted green. Check their condition carefully.
Porsche has gone to copper alloy lines that do not rust or corrode. If you have any concern at all with what is there now, I would replace with the new alloy lines. They are a tan/gold color. I will look to see if I have a photo to post.

Len

[RWebb]

I think everyone uses those copper alloy brake lines now - the VW Vanagon rebuilders are buying them in the aftermarket somewhere.

You might be able to find a fiber endoscope that would fit inside the lines allow you to inspect the lines quite well.

If the car has always been in Washington (as in PNW) then I would not worry about metal fuel or brake lines beyond inspecting accessible areas from the outside.

[BoxsterGT]

lost-

Just curious as to what you have done w the fuel lines/hoses & tank?

Also, there are lots of threads here on Pelican of the woes of "coating" the inside of the fuel tank. I think mostly with CIS tanks that have a plastic swirl pot inside, but nevertheless its a concern.

I have a early tank that is due for reconditioning. I am debating the same thing, "to coat" or "not to coat".

Len

[enzo777]

Hello i do that work in my targa 1972, las week.-
i not have problem with line, made of steel inside tunel.-
i only change rubber from tank to steel line, and in rear of car steel line to gas filter, and to carbs.-

if have 2 rubber lines in tank, one is to return high presion line , if you have inyection system.-

my car was, fuel inyection, now is carbs, i need only one line tank to filter and carbs.-

about lines of fuel and fuel vent system, please look
1972 plastic engine cover holes

regards
E nzo