I recently worked on my 1980 RX7 and got it running. When I took it for a drive, after 5 minutes, the engine sputtered, lost power, and quit. I added some more fuel, got it started, then it did the same thing. Then I noticed fuel leaking out of the top of the gas tank and dripping down.

After a while, I got it started again, and then it died on the way home. After waiting about 45 minutes, it started, I saw fuel drip out again, but was able to drive the short distance home and park it. But I still smell fuel.

Any idea what is causing the problem?

Thanks.

 

Maybe a plugged vent line. It's time to rehab all the old soft fuel lines that go from the tank to the fuel pump and connect to the hard lines. Might as well replace the tank vent line.

 

jack the car up, start it and search for the leak. it is a good idea to replace the lines like kansascityrepu mentioned as there probably old and gone brittle.

 

Time for all new fuel line, from tank to pump, pump to hard line, and hard line to carb. Give all those a try and let us know if you find any old cracked soft lines!

 

How can I access the fuel/vent lines on the top? Do I have to drop the tank?

 

Change your fuel filter!
These should be changed EVERY YEAR!
Under car in front of Driver rear tire.
I'm guessing the prob could be INside the tank. Old cars, esp those that have sat unused for long periods will have rust/grunge collect inside the tank. These tanks are metal, and sitting with little or no fuel leaves a big air pocket in there that creates a cloud of moisture that just sits there eating out the inside of the tank. One of my SAs had your problem too. Start-drive-stall-sit-repeat. What was happening was the crap in the tank would get sucked into the Outlet and plug the fuel filter. The car stalls, you shut it off, the debris floats away from the outlet till you restart the pump. In my SA it was particularly bad with a ½-or-less full tank.
Anyway - only solution was - yes -drop the tank, clean it (rad shops do this) and re-seal it. I used por15.com's fuel tank seal kit. You need to re-line it so the insides are sealed up and won't start rusting all over again.
There is NO drain plug on the SAs (79-80) so you need to remove the Driver side rear wheel, remove the plastic gas tank shield and remove the fuel-sender to drain from there. You do NOT want to be juggling a heavy, sloshy tank of gas down from under the car!! 2 straps hold the tank and its a straight forward removal ( when _empty_).
Yes most of the lines run up to the TOP of the tank. Take special note (photos!) of which line goes where, there are 4!

Even if its just a bad line, since you prob have to pull the tank, its worth it to clean and seal.

Stu
80GS
Alaska

 

Thanks.

I previously flushed the tank and fuel lines all the way to the carburetor, plus replaced the fuel filter, fuel pump, and fuel lines underneath the car.

Whatever us causing the problem is on top of the tank. So it sounds like I have no choice but to empty the tank and remove it. Those are the only fuel lines that I have not replaced and assume age has finally caught up with them.

 

It will be good to replace them any way, one of mine pretty much fell apart