So my car does start, but it needs starter fluid in the morning or after sitting for a few days. After it has started it works fine and does not have any issues starting. I am looking for repair manuals or suggestions if you know anyone who has worked on them. I am thinking its the coil and might need a resistor on top to help it start.
Does it have Bosch K-Jetronic (CIS) fuel injection? If so, that has a "cold start" injector that adds additional fuel for a richer starting mixture (same function as a choke on a carb) which may not be working.
Yes you are correct, the injector is not working. Further looking into it the injector does not seem to get any current when starting. Any idea where I can get a repair manual for the car?
You might be able to find a manual on ebay or from a used book seller. It's also possible that Mercedes still sells them, they make a point of carrying parts for and supporting their older models - though I'm sure at a stiff price. A quick internet search came up with this manual in electronic form at a reasonable price:
That's a mechanical fuel injection system and it was used on many European cars from 1970s through the 1980s (Mercedes, Saab, Volvo, VW, and more). I'm most familiar with it from the old 8-valve Saab 900. I haven't owned a Saab with that system for years but it should operate basically the same way as in your Mercedes. According to the manual I still have for it there is a "thermo-time switch" that operates the cold start valve when the engine temperature is below 113 degrees and the starter is running. Since from what you're saying there is no current at the cold start injector when cranking the cold engine that would mean that the thermo-time switch (or Mercedes equivalent) is bad, or wiring is bad, or possibly a fuse or relay. (On the Saab engine that switch is located on the intake manifold. Probably similar on yours.)
Grounded the wire which goes from the injector to the thermostat relay. It works now.
Great, every once in a while you get lucky!