How shoud i clean out my gas tank?

[mk3-4-me]

So i decided to take out my gas tank because thats the only thing i can think of that is keeping it from starting. When i got the car it had about half a tank of some 3 yr old gas in it. After talking to some ppl at local auto stores they said, instead of siphoning it all out, just put a bottle of sea foam and the rest with some good gas. So i did that. And still no fire up, just a couple putts here and there. So i decided i need to clean the gas tank out.

well i finally got my gas tank out.I emptied it all into buckets. The gas does look a lil wierd, but idk if thats just cause im hoping this is the prob. lol

But what should i use the clean the inside with? There r little black bits chillen in the tank and i want to get them all out.

and is there anything i should check on my fuel pump to see if its good or bad? idk i just wanna do everything i can since i have the tank out.

THANKS!!

 

[destrux]

Ah, yes, seafoam. The only thing in this world that's got a more powerful reputation than chuck norris. I hear he started drinking it now instead of beer.

You can buy stuff that's made for cleaning the insides of metal fuel tanks. It's a 2 step cleaner made by Kreem called tank prep. It's actually made to strip the inside of a gas tank down to bare metal and derust it in order to prep it for a fuel tank coating that they also sell. The coating works good too, if you have any rust in the tank it covers it up. Just don't use it if you run E85 fuel. I don't think it's compatible. I used this stuff on a rare fuel tank for a sportbike I was restoring and it has been holding up for 7 years now.

Part "A" gets rid of varnished fuel and gunk from the tank, and part "B" gets rid of the water from step "A". Leaves the tank bare metal inside.

If you don't want to try that stuff, just put some paint thinner in it and some pieces of chain and rattle it around for a while. Then flush it with more thinner and let it dry before you put gas in it.

As for the fuel pump... you're pretty much stuck waiting to test that till everything is assembled again. You'll need a fuel pressure gauge. To test it at idle for basic function just hook up the pressure gauge and disconnect the vacuum from the fuel pressure regulator and check the base fuel pressure. The specs are in the TSRM. It's important to also check it above idle or free rev though, because the engine demands more from the pump when the car is under load. Just watch for pressure drop when you accelerate. Keep in mind the fuel pressure goes up and down with the vacuum regulator, so pressure will go up to to base fuel pressure at WOT on an NA and will go up above base pressure 1:1 with boost pressure on a turbo.

Probably a good time to change the fuel filter too.

 

[boostcraver]

If you had half a tank of bad gas, the pump was likely submerged and all the seafoam in the world won't free up that sludged up pump. Yes you should replace the pump while it is out and maybe clean the sending unit as well. While the tank is out, it would be MUCH easier to replace the fuel filter as well, rather than later with the tank back in the car. I had this situation when I bought my current money pit. It had been sitting for about five years and the tank was fubar. To clean out the tank, I opened the drain plug in the bottom of the tank and flushed about five gal. of gas through the tank 3-4 times. I used the same 5 gal. and filtered it through a cheese cloth as it drained to catch any clumps of goo and keep them from getting redeposited in the tank. I thought the fuel might be your problem! BTW, seafoam is a waste of money. Good luck and let us know how it goes.

Edit: So I just finished typing all the above, Posted it, Then realized that someone else had posted virtually the same thing while I was typing. Consider the above a +1^

 

[mk3-4-me]

lol thanks guys i think ill flush some old gas through there a couple times..