Pull the distributor and check the condition of the trigger points. Also check for play in the distributor shaft -- if the bushing at the bottom is worn, you will get excess oil on the trigger points AND the pressure from the igintion points can cause the left side trigger points to fail to open, especially if they are worn.

Trigger points are in the bottom half of the dizzy, you must pull them to check. Inspect the plug, too -- if the wires are broken or unsoldered at the plug, you won't get injection. You must pull the dizzy to get them out. Check with a VOM for contact. Spray them out with brake parts cleaner to remove all the old oil and crap. DO NOT attempt to remove the plastic covers, they will break if you do, and you need them.

I'd not worry about injectors until you get the trigger points working -- no signal and they won't inject.

finally, there is a big rat's nest of grounds up on the firewall (behind the battery on the W108, don't know where on the W116). Take this loose and clean all the wires, grease, and re-install. All of the injectors ground here individually, so if part of the bunch isn't connected due to corrosion, the injectors won't work. YOu can test with a test lamp or VOM at the injectors with the engine running -- you will get fluctuating voltage at the injector "hot" wire if the ECU is firing the injector.

My W108 cold starts on 4, then 6, then runs on 8 when warm -- I believe this is because the ignition points push the dizzy shaft to the right, and when the trigger points are cold, they wont' fire some of the injectors. A Pertronix or Crane breakerless ignition will help a lot here, as removing the points takes the pressure off the dizzy shaft and it tends to run much more vertical, opening the trigger points properly.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!