should I worry too much about this:

My 87 420 sel starts fine in the mornings (turn the key and it starts the first time). But it takes 2-3 times to start it in the afternoon after sitting under the texas sun for 8hrs. Just wondering if the 100 degree temps have anything to do with this problem.

MOre than likely, your OVP, or Overvolt Protection Relay is faulty. DO A SEARCH!

I have had the same problem with my 89 190e, lived with it for too long, replaced the OVP relay and it runs like new. Apparently, the faulty relay was the cause of several other problems with my car including the A/C and Cruise Control which now operate perfectly. On my car the relay is behind the panel directly behind the battery. It is the relay with one or more fuses on the top. (old relay had one fuse, the new relay had two fuses) The relay pulls straight up and out of its socket. However, putting the new one required taking out the two relays next to it. Cost of the part was $70 at local MB dealer.

OVP relay
 

Hi folks it seems that this relay is responsible for a ton of problems, but does any one know what the actual failed component in the relay is? I have recently had the fuel pump control relay replaced on my 300E (£109.00 in the UK.) I have the old one back and will try and find out the failure cause. There must be good number of Electronic Techies out there that have done this exercise before.
Regs from the UK
Bob D

Is there an OVP relay on a '76 450SL? I have hot start problems too and am just starting to trouble shoot. If there is one, how do I test it?

Thanks

From some of the threads I've read regarding the OVP, the electrical techs have determined poor soldering as the cause. Some have even gone as far as resoldering the joints on their old OVPs, thus "restoring" them back to usable condition.

Don't know how far back the OVP goes with regard to model years, so I can't say whether the 76 SL would be plagued by that. Maybe an MB tech here can answer that.