A couple days ago I posted a question about a fuel problem on my car in that when first cranked, the car would run fine bu after a couple of minutes the fuel pressure would begin to swing up and down, and eventually drop so low that the car would stall.

At first I blamed the suction line to the pump, maybe being clogged, and then maybe the pump failing.
Well today I ran the car will a hose in a gas can and it still had the same problem. So, I took the filler neck of the tank for a look inside and saw what looked like a piece of rubber stopping up the return line.

So, I drained the tank, and took the line barb off, and presto. a completely plugged return line.

Another one.

I also cut the end off that compresses down so that there is a full flow through the line.

Inside the tank I also saw that the return hole is only 7/32'' (.219)dia.
I drilled it out to 5/16'' dia.
I put the tank back in the car, and put a gallon in it and now looking through the filler access hole with the car running, there is some serious agitation going on.

The fuel pressure in now fully adjustable.

On a related note.

I am posting a couple of pics of the inside of my horrible gas tank.
What you are looking at is the reamins of tank sealer.

several years ago I bought a gas tank restoration kit from Eastwood Company. I used it on my then bad tank, and followed all directions explicitly.
I thought it turned out okay, but 7 years on now, the sealer has completely failed and is peeling off in sheets inside the tank.

Word to the wise on using these do it yourself home kits. It may work well for someone else, but it didn't for me.

See for yourself. Does anyone have a source for new repo tanks????

Ron

Last One.

Ron

That looks nasty ...

PMS makes a nice fuel cell that is shaped like the stock tank. Pricey, but very nice ...
http://www.patrickmotorsports.com/part/214/

Andy

I'm glad you found your issue. A plugged return line makes perfect sense.

On the tank note, I don't believe anyone makes repro tanks, but I do know that there are better tank sealing kits. I've used Kream (which looks like the Eastwood kit) and it worked horribly.

McMark recommended a kit by Caswell Platings which has worked really well for me on a few tanks. Its essentially an epoxy, not the paint-like coating of other kits and it seems to adhere extremely well. I've used it on both steel and Al tanks with great success; the stuff is literally as tough as nails.