I have a mint 1989 560 sl the third from the last made. Lately I have had trouble starting the car the second time around. If it does not start the first time I turn the key it keeps turning and turning while laboring to turn over. Sometimes when I place it in neutral is starts. If it does not start right away I have to let it set for about 15 minutes to an hour before trying again. Car has 62,000 babied miles on it. Any help? Don't want to start in getting in the guessing game with this car and my wallet.

Most likely issue is fuel pressure bleed-off. Testing fuel pressure w/ gauge would be my starting point.
Most common bleed-off failures are; fuel accumulator, fuel pump check valve, OR injectors.

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