I know this had been covered a number of times - just wanted to share my experience: 1972 164E runs until the fuel pump sounds like it is breathing its last then the car quits runnnig for a little bit. Sound familiar? So, I finally took the fuel tank off the car, pulled the internal filter out, and found it packed with reddish colored "mud." The tank was dry, and when I picked it up it sounded like there was gravel in it - when I rinsed it out 1 & 2 inch chunks fell out. I am now "cooking" the tank with crud remover, and hope to get it rinsed out, and put back in the car this weekend. Who knows, maybe I'll start running corn squeezin's in it! That'll really clean it out. ;>)

I count myself lucky that I didn't burn up the fuel pump - it was working so hard.

Kent