I just picked up a 87 300E and drive it home. It ran well but alternator is no good so I have it parked in the garage till I have achance to replace it. While its in the garage I figured I would go through it and straighten out the interior and clean it up a bit. I started it with a strong charged battery and while it was idling it just quit[:@]. No fuel or spark. I checked for both. I have fuel to the fuel distributor but not at the injectors and no spark[&o]. I just put new plugs in it before I drove it home and it has been sitting for 2 years previous to me purchasing the car. Should I be looking for a crank sensor failure or ignition control module gone bad? All the fuses are good and I have power at all points at the fuse box. Just seems odd to loose both at the same time it leads me to think it could be the ECU if there is such a thing in these vehicles. I am a technician by trade but work on american and japanese vehicles not european. so any help in the right direction would be great.

 

You think you have an alternator problem, but it most likely is the voltage regulator. Try replacing it first. It is cheap (less than $40.) and a piece of cake to replace. replacing the alternator is real PITA
The no start issue could be related to a weak battery (OVP, low fuel pressure, and other possibilities)