I don't think the timing chain stretch will prevent your car from starting. It might put your timing a little off, though.

You probably have other problems.

How long has it been since the timing chain and upper rails were replaced anyway?

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".