My 190E has had some problems starting. Cold-it starts easily. Warm-difficult with one or two cylinders catching after some time then it finally has all six firing. I figured a fuel pressure problem and I was all ready to pull the checkvalves when a new problem started today. Once the engine warms up, the idle surges between 1400 and 1800 RPM. It will surge four or five times and then settle down to about 600 RPM (which seems low to me). Plugs, wires and distributor cap are new. K&N filter in good shape(nothing obstructing). The checkvalves may be the problem for the hard starting, but the idle surge has me baffled. Any ideas? Thank you and Happy Holidays to all.