1972 Challenger Gas Tank Venting

[ol72]

I could use some good advice. My mechanic ripped out all my gas venting lines from the gas tank when he put in a replacement gas tank. He soldered all four vent holes and then removed the charcoal cannister. Now I have a constant smell of gas when the car is in the garage. I checked the new tank and it appears gas is being forced out around the sending unit. Also, my gas gauge is not working, we have replaced the sending unit three times with no result. The car is lurching during acceleration. Is this a mess that can be fixed? If so, please give me some ideas. I can not find drawings anywhere that show how I can fix these problems.
Thanks
ol

[Challenger_Nut]

One fix would be to heat the solder and remove it from one of the nipples. Then you can run a legnth of fuel hose off of it with a small in line filter attached to the other end of it. Then attach the filter end as high up as possible to the top shock mount cross member with a zip tie. That will allow it to vent.

I believe you know the other solution. $$$$

[Rallye72]

I looked in my shop manual, here's what I think you need to do to unscrew this:

As "Nut" stated: get the pipe (all of them, not just one - by the book) unplugged. Reconnect them via rubber hoses from the tank to the "vapor liquid separator" I'm assuming your mechanic didn't remove that device. There are (or should be 5 lines: one leads to the charcoal cannister, the others relieve the pressure from inside the tank from each of the top four corners of the tank. One of them (the shortest inside the seperator) serves as a return hose back to the gas tank. All of these lines are at different heights inside the seperator to account for parking angles and maneuvers. The tallest feeds the charcoal cannister which serves to "store fuel vapors from the fuel tank and carb bowl." You don't have to have the cannister, most folks took them off, but I think it helps cut down on vapor oders.

As far as your gas gauge I'm willing to bet he threw away the ground strap at the fuel tank. I've had this problem in the past and it was typically a ground issue. As far as the lurching I'd guess it's fuel starvation because as the fuel is sucked from the tank it creates a vacuum inside the tank that effectively prevents the fuel from flowing evenly (that's a guess on my part, there may be other reasons).

If you can't reverse the handiwork I think Nut is correct: you'll need another fuel tank. I also strongly recommend that you get a shop manual on CD for your car, mine has saved me countless times especially wrt electrical problems. Good luck.

g

[ol72]

I'm sure all the parts to the system were tossed in the garbage. I surely appreciate the advice and I will pick up a CD ASAP. Live And Learn!
Thanks!
Owen

[Challenger_Nut]

How many nipples are on your sending unit? If you have two you can use one for the vent (The non ECS or EEC units have two). I am currently running this set up on one of my cars. Not all tanks have the four nipples.

[Challenger_Nut]

BTW Did you check the lock ring on the sending unit to make sure the mechanic got it tight enough?

[ol72]

Challenger Nut,
I'm almost positive there is only one nipple on the sending unit, then the post for the electric connection. On the lock ring, I'll have him double check it.