1989 300 sel cold start problem
 

Ok so recently i bought a new (to me) 300 Sel. so me and my dad get on it replacing things on it like injectors, pipes and some rubber. But one thing we can't figure out is why the cold start isn't working at all! We checked and power isn't getting to it and we're wondering what controls it a computer some thermometer? We went to autozone for a manual but they didn't have any for my model.

103 engines : OVP , Overvoltage relay goes bad and so does the fuel pump relay. causing problems.
i would start by removing the OVP cleaning the pins and re installing with a fresh fuse in it. With age the inside soldering deteriates and voltage does not get to cold start and other systems.
for reliability you will find replacing the old fuel and over voltage relays is best .
mak
300se

what I would look at first here is the coolant temputure sensor...it's the very first thing the computer looks at for status of general engine state.
General Engine State would be a great song/band name...anyway...I would start with the old coolant temp sensor...it's cheap (around $25) and fairly easy to replace and you will end up doing it anyway....best of luck

so i checked the ovp relay, and too quickly i thought that was it, since the rpm went up and the car actually held idle and then the rpm went a little down. But turns out the next day my dad tried to start the car the next day and it wouldnt hold idle and warm up. so that only fixed the abs lol. ill have to take a look at that temp sensor and play around with the other relays. thanks for the posts