Gas leak / motor not getting gas

[dnotton]

Hi -- I have a 73 240z that has a very strange problem. When the gas falls below a certain level in the tank it stops drawing gas to the float bowls and SU carbs. To get it started again all I have to do is put in a gas can full of gas and it starts right up. I also have a leak around the fuel sending unit. Does anyone know if these are related? If I fix the leak will the other problem correct?

[sblake01]

Sounds like you have a hole in the fuel pickup or a broken fuel pickup.

[Diseazd]

A 50 cent O ring will fix your sending unit leak........Drive off the lock ring with a screw driver....pull out sending unit and old O ring.......install new O ring, then repace unit and tap around the lock ring.

[sblake01]

And you're going to want to fix that........but that won't fix the fuel delivery problem.

[dnotton]

I'm a total novice. What is a fuel pickup and can you tell me anything about fixing it? Thank you!

[dnotton]

OK, I think I got it. It's a straw like metal tube that goes down into the tank that sucks gas out. There is a hole in it that makes it suck air instead of gas when the hole is above the gas level. That's bad news. That means I need to have the tank removed and opened up in order to fix it right? Ouch!

[sblake01]

There is another fix though it sounds somewhat temporart to me. I can't find the thread right now but IIRC, it involves moving the pickup hose to a fitting screwed into the drain plug hole and capping the original tube.

[JimmyZ]

Get under the car and make sure that the rubber fuel line which runs out of the tank isn't your culprit. If it is cracked it could cause both symptoms. When removing the old line cut it lengthwise with a knife after removing the clamps. Trying to pry or pull it off might crack the solder on the pickup or return tube. (= trip to radiator shop and a few $$$)

It might also be possible that your fuel pump is on it's way out. (Rubbers are developing cracks) It might not be drawing fuel well when it has those few extra inches to work with. It might not hurt to change the fuel filter as well. A fuel pump which is spaced from the cam wrong won't pump well either. There should be a phenolic/plastic spacer between the pump and the head. (black or orange in color) This spacer gives the proper distance from the cam to the fuel pump arm.

I find it hard to imagine that the pickup tube would be rusted through though. (Not to say that it's impossible) When I cut an access hole in my tank for sandblasting I found the pickup tube to be made of thick steel. The problem is most likely to be found in a rotted or loose rubber line, the pump or fuel filter. Check that all rubber fuel hoses around the pump are free of cracks and are properly clamped. It's cheap enough to replace the fuel hose so I'd just give that a try.

Be very careful when working with gas and gas tanks. Don't work indoors and if you spill any fuel wait for it to dry completely before doing anything which may cause a spark.

Here's a page with some pics of the inside of a 240Z gas tank. (Pics at bottom of page)

http://warbuddies.homestead.com/gastank.html

2c

Jim

Edited September 3, 2008 by JimmyZ

[dnotton]

Thanks guys, really appreciate your expert advice. I'll see what I can do without going the route of removing the tank and having it repaired.

[Diseazd]

Jim........That is the most awesome correct fix of a gas tank that I've seen! Beautiful job! My friends who runs British Car Service in Richmond, Va. cuts his and has them galvanized. He says it ain't that expensive. Thanks for a good thread. Guy

Edited September 3, 2008 by Diseazd

[JimmyZ]

Jim........That is the most awesome correct fix of a gas tank that I've seen! Beautiful job! My friends who runs British Car Service in Richmond, Va. cuts his and has them galvanized. He says it ain't that expensive. Thanks for a good thread. Guy

Thanks Guy,

Does your friend know someone who does hot dip galvanizing? What process does he use if not? That method would be the best. With alchohol being used in fuel more and more the galvanized tank method would be king.

Using RedKote was the best compromise for me. Prior to using a coating such as this I was looking into nickel plating or some other creative way to blow some $$. The galvanizing route would be cheaper and better in the end. If a tank were prepped and galvanized with some good buildup then it should last forever. If I get 15 years out of the RedKote I'll be happy.

Curious,

Jim

PS Dnotton... Let us know how it all works out. I'm betting it's simple and not too expensive.

Edited September 3, 2008 by JimmyZ

[Diseazd]

Jim.......I'll check with him and let you know.....you can probably google local metal works places in your area....Jim said it was only $20-$30. Guy