560 SEL GAS ENGINE HARD TO START - INJECTOR SEALS?

[MikeMay1]

I have an 87 560 sel. 17 years now, 415,000 miles. Great car. Gas engine.

Past 4 months, the car has been harder and harder to start (5-7 sec cranking), but once started, runs ok. If it sits for 10 minutes or more, it becomes hard to start. Used to start ok in the morning, but now that's hard too.

Few months ago, as the engine was running (little rough), mechanic squirted degreaser near injector banks, and it smoothed out. He tweaked the fuel mix to smooth it out, but startup is still the problem.

We surmise that the injector seals are bad, fuel drains back to low spot. Injectors replaced 3-4 years ago (2nd replacement).

I want to replace seals the seals and needed plastic/rubber parts. Any one give me links or directions, it would be appreciated. thanks.