Update on '86 5-speed 300e
 

Ok here is the latest in my fight with this 300e. Got car to run, has copper core plugs, new wires, new cap and rotor, checked fuel flow after pressure regulator, checked fuel flow through distributor and had to adjust the Electro-Hydraulic Actuator as its flow rate was around 800mL at first at WOT. Got it down to 300mL. The issue is that it starts but goosing the throttle causes the engine to die. I can get it to rev properly by manually manipulating the air flow flap with the throttle. I did the flow test by running fuel lines to little bottles, jumping the fuel relay to always run, and dropping the hammer, on the air low plate, to simulate WOT for 60 seconds. After 60 seconds I remove the hammer and measure the fuel. What are some other things I can check to troubleshoot this issue?

Well readjusted the flow to 1 liter at WOT. Now have better throttle response. Now a new issue... the oil pressure drops to 0 slowly as the car warms up and at that point the rockers start tapping. Is this an issue with the oil pump pickup slowly catching debris and clogging it, then settling when the car is off. When the car cools and is started again the cycle repeats... Should I flush out the oil? How does one do this, just pour it in with the plug out or use some solvent?

My first thought is that the pressure drops with the viscosity as the oil warms up. How many miles on the engine, and what kind of oil is it?

High mile, i'd say around 160,000 or higher. 10w-30 oil, fresh outa the bottle.

One other easy check - oil filter. Make sure it's the exact right one for the car. There are some similar ones out there that fit, but don't work right, as I recall from my long-departed M102.
Beyond that, worn bearings can cause low oil pressure, but you would probably hear knocks and such from them as well. I guess your shorn off cam lobes could have been due to oil starvation, which could point to a bad pump or clog somewhere.

Likely the timing chain guides disintegrated causing the clog.

Try draining the oil HOT, and put a screen or something over the oil pan to catch any stuff.

Yup, the tensioner was too high and the chain chewed the guide up. Switched to a 2.6L engine block and cylinder head from a '93 190E and plugged the exhaust port that would go to the air pump. Moved everything over from the 3.0L and got it back in the car. The motor isn't getting fuel. It runs with a can of starter fluid sprayed into the air speed sensor assembly. Tripped the fuel pump to run constantly and took off a fuel line going to injector #1 from the fuel distributor and with the air flap all the way open there is no fuel coming from the top of the opened port on the distributor. There is gas at the fuel inlet port on the distributor. Popping off the EHA shows gas there. I am hoping the distributor hasn't failed all of a sudden after the car sat over the winter in the car port... I tested the voltage at the EHA's connector and show 7v, and on my 190E it shows 13v. Not sure how much of a difference it can make. Any ideas are welcome. Tomorrow I plan on swapping the air speed sensor assemblies between the 300E and my running 190E to see what happens...

Update: Got the fuel distributor to spit fuel through to the injectors now. I swapped the Air Flow sensor assemblies back and forth and somehow it started working again on the 300e. *shrug* Car fires right up but stalls after 3-5 seconds. If I'm quick and get to the throttle lever and air flow flap in time I can keep it running by giving it just a hair of leverage on both, but once I release them it dies. It has a new OVP from eckler's and I've done the flow test on w124-zone-dot-com. New plugs, wires, cap, rotor, and keeps running with starter fluid. Any thoughts?

Update: Swapped on an 89 motor and it fires up but runs rough. I had a 93 190e and pulled the resistor that hides behind the ECM and battery on the 300e to use in the 190e to resolve an issue with it running rough and the 190e is now long gone. Does anyone know what resistance that was?

Found it: 750 ohm resistor = 6 degree retard (standard in US car)