Gas Tank Question

Ohio Tiger

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CAT Member
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35
Hey guys; my Tiger just came out of a three year restoration. Finally. It appears that gas is not flowing into the drivers side tank. I can only get 6.5 gallons of gas into the car, and the gauge does register half full when it is "filled up". The gas is going into the passenger side, as it comes right up to the neck when full. Any thoughts on why gas is not going into the left side tank? Thanks for your help.

Bill in Ohio
 

HolyCat

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1,241
Just Some Thoughts

Bill,
If your gauge is reading half full, then you are getting some gas into the driver's (left side) tank. The first thing I would check is the breather pipe or vapor line that comes off the top of the left tank. I suspect that there is a plug somewhere in it or in one of the two nipples that this hose connects to. This would cause an air pocket in the top of the left tank, so that when fuel goes into the right tank and tries to fill up the left tank (via the large pipes connecting the bottoms of the two tanks), there is no where for the air to go and the air compresses some (and maybe some of the compressed air does get through the vent line, but it still holds pressure). You can test this by disconnecting the vent line from the tank and sticking a wire down the nipple on top of the tank. Test level by tap on the side of the tank. If my theory is right, the level in the left tank should equalize with the level in the right tank.

Be sure to do this in a well-ventilated area and away from any ignition sources, such as water heaters or furnaces. We don't want anything bad to happen to you or your car. Good luck!
 

tigerracer

Silver forum user
Messages
73
Bill,
If your gauge is reading half full, then you are getting some gas into the driver's (left side) tank. The first thing I would check is the breather pipe or vapor line that comes off the top of the left tank. I suspect that there is a plug somewhere in it or in one of the two nipples that this hose connects to. This would cause an air pocket in the top of the left tank, so that when fuel goes into the right tank and tries to fill up the left tank (via the large pipes connecting the bottoms of the two tanks), there is no where for the air to go and the air compresses some (and maybe some of the compressed air does get through the vent line, but it still holds pressure). You can test this by disconnecting the vent line from the tank and sticking a wire down the nipple on top of the tank. Test level by tap on the side of the tank. If my theory is right, the level in the left tank should equalize with the level in the right tank.

Be sure to do this in a well-ventilated area and away from any ignition sources, such as water heaters or furnaces. We don't want anything bad to happen to you or your car. Good luck!

I had this problem with a customers car that I restored. I found on the new filler hose, where the vent tube from the drivers side connects, a thin flap of rubber left from the moulding of the hose, blocking the vent hole. With the vent hole plugged, it would only allow the left tank to fill partially, while the right side tank showed full. Open the gas cap, and using a piece of wire, insert it into the vent hole, which is about 2" below the top of the filler hose, making sure the vent hole is open.
 

HolyCat

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CAT Member
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1,241
I had this problem with a customers car that I restored. I found on the new filler hose, where the vent tube from the drivers side connects, a thin flap of rubber left from the moulding of the hose, blocking the vent hole. With the vent hole plugged, it would only allow the left tank to fill partially, while the right side tank showed full. Open the gas cap, and using a piece of wire, insert it into the vent hole, which is about 2" below the top of the filler hose, making sure the vent hole is open.

I had never heard of the problem with the new filler hose, but this would appear to be the likely location of the blockage in the vent system for the left tank. Good reminder for folks to look at the filler neck hose when installing a new one. Thanks go to Dale for identifying this issue.

So, Bill, have you had a chance to see if this solved your problem?
 

Ohio Tiger

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Messages
35
Have not had a chance to run down the suggestions. Will soon. Thank you so much for the responses. I will report back shortly.

Bill
 

0neoffive

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2,853
Sand Piles

Have not had a chance to run down the suggestions. Will soon. Thank you so much for the responses. I will report back shortly.

Bill

Here, in the damp east, we have wee insects that like to cement any idle orifice with sand nests. The carbs, vent tubes & other plumbing become breeding tenements. The gas tank cross vent is an area we've learned to peek at with every long-stored project.
 
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