Likely not the fuel filter, I would begin to suspect the coil, it can still be bad with a good resistance check, its the load and the temp that hurt it, and maybe check the ignition module, I hope it is not the module, they are way hard to get and expensive. If it is losing the spark after start up, it must be the ingition system some where I would think. Ask MBDOC, he is a wizard with MB troubleshooting

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Christopher Henkel
1990 190E 2.6 - Arctic white SOLD
1986 190E-16v - Blauswartze
1993 300CE - SOLD
2003 W208 CLK 320 Cabriolet - Magma Red