Ok, so I've been restoring my 72 240z. It was sitting in a barn for 15 or so years.

It had about a half tank of bad gas in it, so I drained it and attempted to do the por-15 tank sealer kit. I decided I wasn't satisfied with my work so I took it to a radiator shop to have it boiled out and sealed professionally. I reinstalled the tank and put in all new fuel lines. I got a new fuel pump and wanted to see if everything was working up to that point. So I bypassed the fuel filter and connected the gas line running from the tank to the fuel pump and pumped it by hand. The gas that came out of the line had a pretty strong green tint to it. I pumped about 2 medium sized mcdonalds cups full and it was still green. Is the gas green because of residual gas left in the lines or because of some left over sealer? The sealant the radiator shop used was blue.

What do I do to fix my problem?

Maybe the radiator shop put coolant in itLOL

Blue plus yellow does equal green, but I doubt your gas has a green tint to it from residual sealant...assuming the sealant was applied correctly and allowed to dry/cure.

How does the gasoline appear when pumped (or allowed to drain) from the tank, without going through your lines? If it's greenish straight from the tank, I'd say you've got part of it figured out. If not, then you should be able to reasonably assume the issue is in the hard lines from tank to filter.

There is green gas treatment.

http://www.grainger.com/Grainger/STABIL-Fuel-Treatment-5EVX7?gclid=CL_59Y3Bu7QCFcsWMgodeWwAOQ&cm_mmc=PPC:GooglePLA-_-Fleet%20and%20Vehicle%20Maintenance-_-Automotive%20Chemicals-_-5EVX7&ci_src=17588969&ci_sku=5EVX7&ef_id=UNHwEQAACyTYg2x9:20121227211707:s

I bet in is the residue my tank was blue and my gas was green when I had it fixed at the radiator shop just for short time ...

Where I you located ? I am in black Mountain did you have you have your tank done at Tommys? I think I saw it there . I had to go twice because they did not get all the rust out from between the bafels. Ya my gas was green for a bit after . I kind of had a time with them they ended up putting in a new vent tube which they thought was the pick up.