Spannerhead Dot

Datsun 240Z Restoration:
Fuel System, Part I

April 12, 2012 by Matt

Nissan Datsun 240Z Fuel Tank Gas HLS30 S30

Made a bit of progress last night. After draining 2-3 gallons of 8-year-old gasoline-turned-varnish (below), I removed the fuel tank (above) without too much drama. All three of the evaporative emissions system hoses that intersected the tank were completely shot, so they were snipped (along with a fuel line), but I’ll be replacing all the rubber anyway, so it wasn’t critical. Other than that, all the bolts and screws turned remarkably readily for the first time in 40 years, even exposed as they’d been at the rear of the car. A little shot of PB and everything was peachy.

Bad Gas Gasoline Old Evaporated Fuel Petrol

Needless to say, the garage reeks of old gas now. I’ll probably mix this in with 2-3 gallons of fresh gas and feed it to my lawnmower. The consensus seems to be that it’ll be fine.

Nissan Datsun 240Z Inside Rear Quarter Panel

The really great news was on the inside of the rear quarter panel, shown above. Yes folks, it’s all solid metal. There’s a bit of superficial rust here and there, but based on my cursory inspection, no actual rot. If the car’s structural rust is confined to the passenger side floor pan and rocker panel, I’ll be a happy (relatively-speaking) man.

Given the good condition of the inside of the tank, the question at this point becomes: Should I use the POR-15 Fuel Tank Repair Kit, or just clean and seal the outside of the tank and call it a day? I’ve used the POR-15 kit before (on my old Audi 4000’s tank) with good success, so that’s charted territory. But I’d rather not do more work than I really have to. Hmm.

Editor’s note: This post is Part 13 of an ongoing series chronicling my efforts toward the restoration of my 1972 Datsun 240Z, originally my father’s. Read the other installments here:

Filed under: 240Z Restoration, Datsun, Project Cars, Technical, Tinkering


  1. John D says:

    That’s amazing about the gas tank bolts…but then again, PB is amazing stuff. It’s a staple for my garage chemical collection.

    Part of me says if there’s no problem with the inside of the tank not to worry about it. The other part says that it’s a pretty old gas tank and it might be worth the $80 and a couple of hours to head off potential problems and get some peace of mind. I mean, while you’re messing with the tank anyways you might as well get it all done at once…especially since this is a car you plan on keeping around for a while.

    I wish I was there to help! Having been without a project car for about 3 years I’m still not quite ready for another one…but I wouldn’t mind helping someone else with theirs (since I wouldn’t have to think about it anymore at the end of the day ;).

    • Matt says:

      PB is awesome. It owns exhaust bolts especially. I should buy stock in their company.

      The tank clean-out is actually a multi-day process involving a blow dryer to make sure all remaining traces of moisture are out of the tank, and compressed air to ensure the intake screen isn’t clogged by the sealant… So it’s pretty involved. But I still think I’ll do it. While I’m in there.

      I wish you were too! Wish I could help Aaron out with his FD as well. Why must we be scattered about thus?

  2. John D says:

    Also, how long have you had that aluminum pan? It’s been around ever since I can remember… ;)

    • Matt says:

      It’s my dad’s pan, so…it’s probably older than I am. It’s actually about as much an heirloom as the Z is. Without a spout, it sucks for pouring oil (or anything, really), but it’s very easy to clean.

  3. Alex Manz says:

    My 240 had sat for approx. 20 years in a metal pole barn in rural SC before I found it on Craigslist (first owner had medical problems which necessitated the Z’s storage…I bought it from the first owner’s son). I had to have it towed to a Nissan dealer in Greenville to get it running for the 630 mile trip north to Columbus. Its main issue was the nasty gas and the vent hoses. The dealer had the tank boiled, replaced the hoses, new plugs and points…it ran like a champ (I won’t tell you how much the repairs cost, but they were worth it :). I really enjoy your blog…very well written and great photos.

    • Matt says:

      Thanks for the compliment on the blog, Alex. That really means a lot! Sounds like you’ve gone through much of the same fuel system restoration as I have. Isn’t it great to have cars that are so resilient and respond so well to some simple cleaning and tuning?

  4. charles says:

    need help finding vent tank hoses for my 240 z if you if ypou know where I can get them plese help 1972 Datsun 240z

    • Matt says:

      I would recommend Motorsport Auto. There’s a list floating around somewhere on the Classic Z Cars forum with the pre-formed hoses you should buy and the ones you can just use regular vent hoses for. Check there too.

  5. Eric Barnhill says:

    Matt: Nice site, I have just acquired a 1971 240Z with 52,000 miles and is amazingly rust free! (A few little spots, but I’m not complaining). I too, just pulled the gas tank and the hoses were in the shape yours were, the inside of the tank has a lot of “Gunk” in it, any suggestions about how to go about cleaning it out?, also the fuel system seems to be a little different than any diagram I can find, any words of wisdom as to where to find the hoses? And how do you get the filler neck out. Again nice site, please respond to my email address, thanks.

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