So I'm going to be doing my gas tank pretty soon too and I was browsing POR-15's site when I came across this, http://www.por15.com/FUEL-TANK-REPAIR-KIT/productinfo/FTRK/

I don't know how that compares price-wise to other kits but I'm sure it is a good kit.

Hello all, I just picked up a 1971 240Z that has been sitting for several years and am in the slow and patient process of getting her in good enough shape to turn the key and see what I get. I have been following directions and suggestions from other discussions and posts I have found. The other day I took off the drain plug to drain the gas tank but nothing came out. So, I poured about a half gallon in to let some fuel drain through the plug to see if any gunk or anything came out with it. The gas came out clean but I did bend and stick a paperclip around as it was coming out to scrape at the tank and when I did this the fuel turned a very slightly brown color and a few small reddish brown grains of dirt or something similar came out. My question is, should I drop the tank and clean it or would I be fine? Some threads I read said that you just change the fuel filter frequently at this point, but I'm not sure if that is in addition to cleaning the tank or instead of. Any suggestions would be great.

Thanks in advance,

Austin

Hi, Austin, Rick here.

I would definitely drop the tank and have it cleaned out VERY THOROUGHLY if it has been

sitting idle for a long time. Not demeaning any of the suggestions others have offered

(either old school or new), nor your personal abilities, but I would have it done profes-

sionally by, say, a radiator shop.

When we tried to avoid this in Lucky 13, we kept loading up the fuel filter to the point of

NO fuel flow. So we temporarily installed an additional, larger fuel filter inline just ahead

of the tank, with the same results over and over. Finally we conceded defeat and had

Vinny Bedini of Bob Sharp fame, to drop the tank. Vinny showed me the problem: in a

(then) 40-year-old, 101,000 mile car, which had also been in storage for a good while,

there was a good half-inch to an inch of crud (some solidified, some not), in the tank.

Even Vinny said it should be reconditioned by someone relatively specialized, and this

from a guy who has forgotten more about 240Zs and 510s than most people ever knew.

Next, I am confident that POR-15 is a wonderful product for most applications. But I

would be leery about using it in a fuel tank. I have heard that some kind of a chemical

reaction takes place which makes it shrink, with the result that there becomes what

amounts to a "bladder" inside the tank. As the POR "bladder" shrinks more and more,

the capacity of the tank gets smaller and smaller. It wasn't Vinny who told me about

this; but he did recommend AGAINST it, and coming from someone with his experience,

expertise, and personal integrity, that was plenty good enough for me!

All Z Best,........................Kathy & Rick

Not to cause any arguing or anything, but from personal experience with por-15 I think it's a great product. I've used it in a few tanks and it has been awesome. However, it's always a good idea to go professional with it too. As long as the tank surface is clean and thoroughly dry, it will not become a shrinking bladder. If you have the money, get it done by the pros. If not, do it exactly like the kit says and you'll be fine.

Chase

Thanks for the input everyone. Right now I'm leaning towards dropping it and taking it to a radiator shop rather than going with a kit. I will probably go check out the swap meet next month as well though. Chase, any idea on the location of it? And is it exclusively Z's, exclusively s30's or any kind of vehicle?

I have cleaned two tanks in the last 6 months, the 520 and Patrol. Here is my experience, based on input from jfa.series1 and a local radiator/fuel tank repair shop’s recommendations.

1) Use a Marine Clean (POR) product or similar degreaser (I used the inexpensive one that Wal-Mart sells.) This will cut the fuel varnish buildup. Add some small stones, old nuts & bolts, or chain link to the tank to agitate and break loose the buildup.

2) Collect liquid from draining tank for proper disposal.

3) Rinse with hot water.

4) Repeat Step 1 -3

5) Rinse with hot water.

6) Take to self-serve car wash and use their hose to spray high pressure degreaser then plain water.

7) You should be able to see through the fuel sending unit hole the inside bottom of the tank. If you cannot see clean metal repeat Step 1-5. If you see rust holes, buy a new tank.

8) At this point you can use the POR-15 tank coating. I have read extensively on-line that the coating may break down over several years and cause fuel system problems. (I chose to forgo the tank coating and primed and painted the tank.)

9) After completing the above, test the sending unit. Obtain a new sending unit gasket and reassemble.

Keith

The swap meet is at Lagrave Field in Ft.Worth, is a meet for just about everythingt with wheels on it. The people who sell the POR product have a big fancy setup that easy to find.

Chase

Drop the tank and clean it with a high-pressure washer. If you don't have one, then go to a car wash and use the high pressure wand to clean out the tank. I have cleaned 3 Z tanks with my pressure washer and fortunately all 3 were nice & clean inside afterwards, so I did not use a coating on any of them. After washing, I stuck a heat gun in the filler tube and let it run awhile to dry out the tank. Then primered & repainted, replaced the sending unit seal (as mentioned by Zed2) and re-installed in the car.

Found out the gas tank has about a mm of rust all the way around, and big chunks were coming out while we cleaned it. Advice?

Ok well I dropped the tank last night and took it to a self serve car wash nearby and 5 dollars later I still had rust particles coming out. I gave up and took it home and repeatedly filled with water, shook it up and dumped it. I did this for probably 20-30 minutes and little rust pieces kept coming out. Eventually I was too tired and frustrated to keep going so I gave up for the night. Any suggestestions on what step I should take next? I stuck a tube light in the tank and there was still a lot of brown in there.

Shake... Harder!

AH Alex you beat me to it!

Another alternative is : gas-tank.com or gastankrenu.com