water in gas tank eradication

My old truck was parked out in a surprise torrential downpour last week. I have a aircraft filler mounted flat in the stakebed. I have never finished off putting in all of the screws and nuts that go around the flange of the filler. I never would have guessed it, but I think that the downpour was so great, some rain water flowed into the flange holes and made it into the tank. I was only a couple of blocks from home, so after the rain I made it home no problem as it ran fine in that short period.

I went out for a drive a couple of days later and the old flathead started missing. It seemed at first sporadic so I pressed on thinking it was just cool, not having warmed up yet. It stalled out on me on down the road. It restarted and would run so long as I kept the revs up. As I turned for home, it started actually smoothing out again.

It was running great before the rain the other day, so I deduced that my laxness in not finishing off all of the fasteners and the amazing amount of rain that fell added up to water in the tank. Sure enough, I used the electric fuel pump to empty out the tank but I first pumped a sample into a gl*** jar. There is definite separation of the two liquids there and my gas is not nice and clear, but kinda milky. I'm thinking that the vane action of the Carter pump whips the mixture into a nice froth.

So, I'm asking all you smart guys, besides pumping out the tank and ****ing all that is left in the carb fuel bowl, what should I do before putting good gas back in? Is there a good additive that will glom onto any remaining water molecules and p*** them along? Thanks in advance for any suggestions.

 

I have dealt with plenty of "contaminated" fuel tanks. Remove the tank, empty it, remove sending unit if there is one and reach in with a scotch pad and scrub the interior of tank clean( might as well since the tank is removed) The reason I scrub the tank is the current fuels leave sediment when left to sit in the tank for long periods..These sediments can clog up your fuel filter usually on a a cold rainy night. Or you can leave the water in and be occasionally har***ed by poor performance.

 

depending on the fuel you probably have enough methol/ethol hydrade in there already. If you use premium fuel which has no alcohol in it you could try addind some methol hydrate that might "grab" the water. If the tank is low filling it up with regular gas may work, it would dilute the already full of water fuel and the methol/ethol hydrate could dilute the water to the point it would burn in the engine. Best bet though is drain the tank the water will seperate out and sink to the bottom, pour of the gas and put it back in the tank leave the water and dipose of it.

 

I use Methyl Hydrate added to the gas but there are additives you can buy, Wynns comes to mind as well as I believe STP also has an additive that apparently will move the water along.
Good luck.

 

If you have a lot of water in the tank, you've got to get most of it out. The water will settle at the bottom, so you can either siphon it, or if you have a drain plug at the bottom, the water will come out first.

Everyone gets some water in their fuel system, especially with alcohol-mixed fuels today. You've probably heard of "DryGas", which is basically isopropyl alcohol. It is used to remove water from gas tanks resulting from condensation from changes in weather. Alcohol mixes with both water and gas, so the alcohol pulls the water into suspension in the fuel mix, and sends it through your fuel system.

 

Iso-heat is what we use in the great white north. It should do the job.

This is what it looks like.

 

Thanks everyone. I pumped the tank dry by undoing the line going to my fuel regulator, disconnecting the coil, and letting the electric fuel pump push the gas into an empty 5 gallon gas can. Initially I pumped about 6 inches of gas into a gl*** mayonnaise jar to confirm my su****ions. In that amount, there is about 3/8" water on the bottom. So, I think that rainstorm must have given me enough water in there for the end of the pick up tube to be pretty well immersed. Fortunately, I only had about a 1/4 tank of gas and I think if I use it, it will be for lawn mower duty. I will try to find some of those additives when I put in some fresh gas.

 

Seafoam.