Now that the problem with my van throwing off the belt has finally been taken care of, there is another issue I'd like to tackle. When we bought the van, the fella we got it from told us that the back tank worked, but that it had a load of bad gas in it. Rather than replacing the tank, I'd like to drain it and give cleaning it a try. My idea is to use a unversal electric fuel pump and a hose to siphon all the gas out of the tank. Then I would put a gallon or two of solvent in the tank and drive it around for a few days so that the solvent could slosh around the tank and do its thing. I would then disconnect the fuel line coming from the tank where it meets the fuel pump on the frame and then pump out the solvent. Assuming that this would clean the tank out, would running the solvent through the in-tank fuel pump ruin it? I've never tried something like this before, so I have no idea if it would work. BTW, the tank is full and the gas is definitely bad in it. I can smell a varnish smell when I take the cap off. It's been this way for at least 28 months. I did put some Stabil in the tank shortly after buying the van, thinking it would help the gas from getting even more stale, but I don't know if it worked or not.

 

Someone's sure to correct me but I'm thinking if you simply drained and replaced the known bad fuel with good stuff, refreshed that tanks filter, perhaps add something like Techron and drove on it alone you shouldn't have to do the solvent flushing thing. Your process seems sound but maybe just a bit of an overshoot?

Does your van have an in-tank fuel pump? If so it might be best to drop the tank and at least replace the inlet "sock" as some floating junk may have collected there by now. For cost reasons alone I wouldn't want to run any solvent through the in-tank pump---could add to your woes.

Just MHO ya understand---others might have another POV!

 

I agree with JWA ....Do NOT do the solvent vibe ....Just drain it / drop it and and open it up and take a look... If it is rusted bad get rid of it if not just clean or replace the fuel intake parts and re-install .....

 

Dropping the tank is exactly what I am trying to avoid. Right now I cannot afford to pay a shop to do that sort of thing. We just paid to have the water pump replaced, so money is tight. I already have one of those universal type fuel pumps, so all I would need to get is the solvent.

 

Shake the truck a bit, drain it and look at what you get. Then decide. The varnish smell is probably the Stabil. The problem with bad gas is the water in it rusts the tank which is a problem that can't be solved. I would say the same for coagulated gas. But, if its just old gas, I say have a look at it before you set your course.

PS: I don't that solvents dissolve anything that gasoline won't dissolve in a gas tank except that they make the water in the tank miscible in the gas (which it is not). You can get the same result with ethanol.

 

Dropping the tank is not difficult.....just make sure it is as empty as you can get it .....you don't need a shop for that......you might need to buy new tank straps to re-install it since when they get as old as yours is they tend to break instead of un screw.....empty as possible is the key....

 

I've dropped them before, and you are right, it's not difficult. It's just that I don't get under vehicles any more. I am not as fast as I used to be, and I just don't think I can get out from under anything fast enough if something were to go wrong. On top of that, my parking area is gravel, and i won't work on a vehicle on gravel or grass. I was willing to do that sort of thing when I was in my 20s and 30s, and quite a bit slimmer, but those days are long gone. My son was helping me with stuff, but he's moved out and has a job that keeps him out of state. If I had a pole barn with a floor mouted lift, we wouldn't be having this discussion, but I don't have one of those either. Hopefully I can get one before I get too old to do anything to a vehicle. Either that or get my daughter trained on the wonders of mechanicing!

 

Since you've already got "the fuel pump on the frame" AND "the in-tank fuel pump" why mess w/adding "a unversal electric fuel pump"?

IF you want to try "a hose to siphon all the gas out of the tank" you don't need a pump. Likely to be difficult to jam hose down filler.

IF memory serves there were no drain plugs on these steel tanks.

The "in-tank fuel pump" has been marinating in the bad gas. May actually do it some good to run it to pump out the back tank? Tap into tank outlet line, don't circulate thru return line. Better check it 1st b/c if pump is DOA you're going to have to drop tank anyway to deal w/it, IF you want to resurrect aux. tank.

IF rear "in-tank fuel pump" runs at least draw off a sample of the bad gas to get a better idea just how bad it is.

IF gas isn't too badly contaminated it should pump out w/o doing harm.

IF gas is far gone solid precipitates and/or gum will clog screen. Bad gas can corrode tank & host bacteria. There is no "slosh around the tank and do its thing" Quick Fix.

Presume the gas isn't so old it's alcohol free? However also presume your van was built before alcohol mandate. Alcohol in gas mixes w/water, shortens fuel's Shelf Life & helps set rust free to clog filter. An old sickly fermented mix can make a mess out of any fuel system, some pre-alcohol components are especially vulnerable.

Big problem is safely handling so much "bad (but still flammable) gas". Have heard some claim they get rid of bad gas gradually, by adding a gallon to full tank of fresh.

Have never heard of anyone using any "solvent" & am curious what solvents make your short list? Traditional strategy was dropping tank & having it steam cleaned.

IF fresh gas isn't "solvent" enough you're probably going to need new pump and/or tank.

 

CW, I didn't think about disconnecting the line at the fuel pump and using the in-tank pump. I figured I'd go with the universal one and a hose so that I dont get whatever is wrong with the gasoline into the main pump. Also, the solvent I was thinking about is the cleaning solvent they use for doing carb rebuilds. I checked today and the varnish odor coming from the back tank is very strong when I take off the cap.