I too have run the gambit trying to get my twin daughters 300E from stalling. I have replaced fuel filters, fuel pumps, plugs, etc..., yet the sporadic stalling continues. It sounds like the air flow sensor POT (i.e. variable resistor) being worn is a likely suspect.

I have cross-referenced the air flow sensor and there are no current replacements from many manufacturers (even though these devices are used for BMW, Audi, and other vehicles as well). I found a shop in Berlin that would sell refurbished units for 177 Euro, but that equated to $246 U.S. (and you had to send in your unit). Gouge...

Since I would bet that they are simply repairing the units with resistive / conductive ink / epoxy as well, I too (like a previous post), took my 25+ years in hardware and software development in that direction and found Stan Rubinstein Assoc., Inc. They have the least expensive solution in the quantities that I need (other sites started at $75 for more than is required). I have purchased both ink and epoxy to determine the best solution and will post my findings here (product is in transit as I write).

Their site is store.sra-solder.com and I ordered 14g of their 2-part Silver Epoxy as well as a Silver Print Conductive Pen. I believe that the epoxy will be a more durable solution but wanted to keep my options open. Combined parts and shipping ended up around $61, so it is worth the trial to me.

Again, if (/when) it works I will post pictures of the steps that I performed. And should it be appropriate I would be happy to help others if they help with the cost of materials and shipping (I am a computer professional and would not be interested in making money from people in a forum that has helped me).

Stay tuned...