Mercedes Benz repair: mercedes check engine lamp, 300se, valve egr

Question
my 1990 300se has no check engine lamp when key is turned on.  shouldn't the check engine lamp come on at start for a bulb check?  also has hard start cold and no high idle at start. i have replaced the e.h.v. valve, egr valve, water temp sender,overlode relay.  please help! runs fine when warm thanx, pete

Answer
If the check engine lamp does not come on, it is damaged/broken.
You need this to inform you when there are issues.

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Your issue is better assisted by them = Tech Help.
There are many similar cases, but they can direct your diagnosis more quickly.