300e Fuel System Problems

I have a 1986 Mercedes 300e that will not start. It was ruuning fine all weekend and then Monday morning, it would crank, but never fire. It has always started with little effort and had no other symptoms up until then. I have checked the spark form the coil wire and the spark plug wires and both have a strong spark. I have checked the fuel pump relay. When I take the relay out, there is no fuel pump noise. After putting it back in and turning the key, I can hear the fuel pump turn on, but it turns off after 1-2 seconds. That leaves me with the fuel system which I do not have a manual for, but I did get the Bosch Fuel Injection Book to read up on it. From reading some other postings, it would seem that I need to look at the fuel pressure accumulator, fuel pump check valve, fuel pressure regulator, cold start valve, and the EHA. Also, I should replace the fuel filter because it might be clogged. I do not know which to check first. Is there an order in which I should go about this and have I overlooked anything?

Thanks,
Mike

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