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Posted by: last337 Jun 7 2013, 06:38 PM

I have been having a lot of problems with my fuel system. I can't tellif it is the fuel pump or just something in the gas tank. I pulled the outlet hose of the fuel pump to try to pump the remaining gas out of the gas tank.however when I did the fuel pump barely put out a trickle of gas. I disconnected the inlet side of the fuel filter in front of the fuel pump and no remaining guess came out from the fuel tank side. I know there was still some gas in the tank but I was assuming that the pressure had locked it up to where no more gas would come out.what I am wondering now is if its the fuel pump is bad or if its something clogging the outlet of the fuel tank. I did put my finger over the end of the fuel pump outlet and only felt a small amount of pressure it was not pushing my finger off by any means. Is it possible that there is a clog on the outlet side of the tank? WhenI start up the engine it runs for a couple minutes and then when it comes under load it dies. If I let it sit for a few minutes the fuel filter then fills back up with gas and then it will run again for another few minutes. Does anybody have any suggestions of where I should go next.

Posted by: Cap'n Krusty Jun 7 2013, 07:07 PM

Remove the vapor recovery tank on the top of the fuel tank, remove the filler neck, and look in there with a bright flashlight. You'll pretty much know for sure whether or not the tank outlet is plugged or otherwise compromised. The return, too, for that matter. The outlet is the one with the screen over it.

The Cap'n

Posted by: last337 Jun 7 2013, 08:26 PM

I have never been inside the fuel tank. Is it easy to change the filter on outlet of tank? How much gas should I remove ? Can I do it with 1/4 tank?

Posted by: --axel-- Jun 7 2013, 08:30 PM

The filter sock is accessed from the bottom of the tank. It is attached to a washer that is locked in place by the nut under the tank at the outlet tube.

Posted by: Mblizzard Jun 7 2013, 08:32 PM

Search for a thread called fuel sock. I don't think it can be done with fuel in the tank. There is also a thread that shows you how to do it without removing the tank.

Posted by: --axel-- Jun 7 2013, 08:33 PM

My bet would be that there is a crimp in the line between the tank and the filter. Have you done anything that would have crimped or kinked the line (i.e. moved the tank or replaced the fuel filter)?

Posted by: last337 Jun 8 2013, 07:20 AM

How do I go about unclogging the tank without removing it?

Posted by: rhodyguy Jun 8 2013, 07:59 AM

where is the pump installed? the strainer/sock will be clogged because of all the crap that is prob in the bottom of the tank. once you manage to get the tank empty, there's always a bit left behind, have a catch basin handy. taking the tank out is pretty simple. you'll HAVE to clean the tank! period. there was a recent thread showing how much loose rust there was in a fellow members tank. amazing.

k

Posted by: rick 918-S Jun 8 2013, 08:14 AM

First do what the cap'n said and us a flashlight to look inside the tank. If it's rusty or there is anything that looks like sediment in the bottom just pull the tank.

Siphon out what ever gas you can if you can't get it out of the lines.

Jack the car up in the front or all around and place it securely on jack stands.

Remove the inspection belly pan under the rack. (four bolts)

Find the fuel lines up in there you'll see them.

Disconnect the rubber lines.


What ever gas is left should start to leak out and run down your arms into your arm pits. If you shave your pits it will burn like hell! I had a gurl tell me that once.

Go back up top. You already have the vapor tank removed from your inspection. Remove the center strap that is across the top of the tank.

After the strap is clear you can wiggle the tank out of the car. There are two rubber blocks, one on each side of the tank and a couple of felt pads that support the tank and keep it from rubbing on the body. Make note of their location. You will need to put these back as you re-install the tank.

Once the tank is out flip it over and remove the nuts that secure the lines to the tank. Order a new fuel sock, clean out both lines. I have seen these clogged to almost no flow.

If the tank is rusted you can use a battery charger to de-rust it. Check you tube. There is lots of info on how-to do it. I did it and it works nice.

Here's a couple photos of my tank.




Oh, and don't reinstall the tank until you replace the plastic lines in the tunnel. We have lost too many 914's to fire from these old brittle plastic lines. Check the member vendor section for a source for stainless line kits.

Posted by: rhodyguy Jun 8 2013, 09:00 AM

rick, what's in the tank when you electrify it? that's an AMAZING picture! wow.

Posted by: last337 Jun 8 2013, 05:53 PM

Well after pulling the tank I realized it was a huge mess inside. The sock looked horrible and there was a whole layer of water separated from gas. So after a pressure washer, a gallon of muriatic acid, lots more water , baking soda, denatured alcohol, and a few hours it books like this. I wonder how it even ran before but at least I found the source of all my fuel system issues. I bet I can finally get my carbs balanced right now

Posted by: turk22 Jun 8 2013, 09:39 PM

That's a great job!

I see this in my future as well...

Posted by: last337 Jun 9 2013, 07:44 PM

I can't seem to locate a replacement sock filter for my tank. Does anyone know where to get one?

Posted by: jbachert Jun 9 2013, 07:52 PM

http://www.tangerineracing.com/stainlessfuellines.htm

The screens are all the way at the bottom on the right.

Chris is a member of the forums and very helpful with any products which are fuel line related. (He sells other stuff, too.)

Posted by: last337 Jun 10 2013, 07:55 AM

Thanks! I found the screen on the Tangerine site. I am wondering how hard it is really to replace those tunnel lines. I really want to do it but it just looks like such a pain. Mine are not that brittle and still can bend a bit where they exit the tunnel but still Id like that piece of mind.

The walkthru I did find was pretty extensive then I saw a video on youtube and it looked fairly easy and he didnt remove anything. I will most likely just replace tunnel line since everything past that is new anyways. Does anyone have any feedback on this?

Posted by: --axel-- Jun 10 2013, 08:28 AM

I just did it by myself. Took about an hour to pull the shifter/console/carpet out, and another hour to run the new line. Add in the time to pull the fuel tank, and you are looking at less than 3 hours. Would have taken less time if I had a helper to help guide the new lines through the front wall.

Posted by: --axel-- Jun 10 2013, 08:30 AM

Also, I did it with the engine still in the car. I did have to remove the right rear wheel to make it easier to feed the line. If you have a lift, this won't be an issue.

Posted by: rhodyguy Jun 10 2013, 08:31 AM

not that difficult a task to switch the tunnel lines out. imho, with carbs you don't need to bother with the return line if you don't want to. there's a recent thread re capping the return line at the tank. as your tank was crappy i'd invest in 10 feet of new fuel line and shouldered clamps to plumb the carbs. of course, toss the old filter. flush your pump (you bought a rotary iirc. if not now is the time). start new and clean, front to back. i think your carb woes were a direct result of the fouled tank and screen/sock.

Posted by: last337 Jun 10 2013, 08:32 AM

Which pieces did you replace? I am a bit confused about what to order.

Posted by: --axel-- Jun 10 2013, 08:37 AM

I purchased the whole kit and replaced everything. I didn't need the new grommets since the old ones were good, but all lines, both stainless steel and rubber, were replaced.

Posted by: last337 Jun 10 2013, 08:37 AM

Well currently I have a Facet pump under the car where the fuel lines exit tunnel. I have an in-line fuel filter just upstream of pump. I always figured it was safer to keep pump under car in case of failure rather than engine compartment but it makes changing that filter a real pain. Anyone ever use a small valve upstream of filter for easy replacement? I was considering just capping return line where it leaves tank. Do you know the size/thread of that cap needed?

Also, do you think I should upgrade to a Carter rotary over my Facet? That Facet has made noise at times but I think it may be due to the junk in tank.

Posted by: rhodyguy Jun 10 2013, 08:43 AM

new lines...front. tank outlet fitting to ss in tunnel.

rear. from ss line @ rear firewall to filter, filter to pump (my pump is a rotary. mounted on the rear fw at about the same elevation as the stock location) pump to tee. tee to each carb.

Posted by: last337 Jun 10 2013, 09:57 AM

Cool that is my exact setup now minus the ss line

Posted by: last337 Jun 10 2013, 10:15 AM

How do I know which line I need? 8mm or 9.5mm? Do I measure that and how do I measure it? Also, do I need that adapter? Cant figure out what that is for.

Posted by: last337 Jun 10 2013, 10:49 AM

I spoke with Chris at Tangerine and I think I got everything I need. ONe thing I wasnt sure of is whether I need to put a sealant back into that tank or not after cleaning?

Posted by: rhodyguy Jun 10 2013, 11:05 AM

get rid of the facet pump.

k

Posted by: last337 Jun 10 2013, 12:48 PM

Should I go with carter instead? How about tank sealant?

Posted by: --axel-- Jun 10 2013, 01:57 PM

Since it was out, I went ahead and had the tank cleaned and sealed at a radiator shop. Cost about $150.

Posted by: last337 Jul 7 2013, 11:40 AM

Well after pulling the tank and cleaning all that gunk out of there and then replacing the fuel lines with ss lines from Tangerine I am back running again. I still cannot believe how much junk was in the system.

Can someone explain how all that got in there? Is that just rust and stuff from bad gas from so many years or what? I was amazed at how clean it came out too. I would think if it was rust there would be pits but it looks great!

Posted by: The Cabinetmaker Jul 7 2013, 12:09 PM

gas is transfered from the refining process to a holding tank, then to a tanker truck, them to the in ground tanks at the gas station, then to your car via an open cap. Lots of opportunity for dirt and debris to enter system. Besides, your tank is now 40 years old and has seen a lot gas go thru it.

Posted by: last337 Jul 7 2013, 01:08 PM

Well there were huge chunks of stuff coming out. Is that a result of the chemical break down of the gas?

Posted by: The Cabinetmaker Jul 7 2013, 02:32 PM

Probably not. Gas turns to a jellied vanish substance. Probably rust flaking.