The engine idle on my 1992 500sl burbles/shutters after about 30 minutes of
running. I'll be at a light for a few minutes and eventually it will briefly
shutter. The car has 65K miles on it.
MB has been over the fuel injectors and replaced many of them but the problem remains. They suggested I try a different
brand of gas and if that doesn't work, they are thinkg they need to drain and "blow"
gas tank and lines.

Any suggestions would be sincerely appreciated!!!

Thanks!!