Occasional miss when fuel level low--300E

[Sludge]

Folks, nobody's been able to pin this one down so any and all help would be appreciated.

Every once in a while (yep, the dreaded intermittant problem) my wife's 92 300E will develop a "miss" or a stumble when the fuel level is below 1/4 tank. Last time it happened to me, the stumble and miss began as soon as I started the car up. Every time I was at idle and tried to give it some gas, it would stumble, missfire, clear up, and then occasionally miss. Sometimes it is worse after going around a sharp corner, and will die completely. Sometimes it will continue to miss even at highway speeds. But it is most noticeable when trying to accelerate the engine from idle. The only cure we've found so far is to fill the gas tank. Naturally, the problem never happens anywhere near a dealer or mechanic. But it has quit just often enough to make us a little nervous about maybe getting hit from behind.

Any ideas would be appreciated. The dealer has checked all the things they can think of, but can find nothing wrong.

Thanks for any and all help
Sludge