Someone poured some laundry detergent/soap into the filler opening of my 300SE. I am not sure how much actually got into the tank due to the restrictor, but before I could clean it all out it rained and I believed a little got washed down into the tank.

What I want to know is, can I just fill up my tank and get away with it? I had little or no gas in it right now. The only reason that I checked the opening was I was going to add gas to the vehicle because it would not start and I noticed the gauge read empty. The vehicle had been sitting for about six to eight months. Any help would be appreciated. We have had a heat advisory here in Phoenix for quite awhile and I don't want to have to work outside to remove the tank.