1992 300 SL - no spark from coil - desperate

[grg334561]

Hi everyone!

as stated above am already desperate as I've done all of the following and still cant' get the coil to generate a spark:

1. Checked / replaced OVP for good measure
2. Checked / replaced / checked for voltage at the Crankshaft position sensor - registered correct resistance and AC current generated during an engine crank
3. replaced Coil , and high tension wires , distributor cap and rotor
4. replaced the EZL (have tested with other M104.981 engines) and works (in fact I have 2 EZL's now because I initially couldn't find another M104 engine to test the first EZL I bought)
5. there is voltage to the coil terminal but during cranking - i don't get a ground into the coil that is supposed to enable a spark from the secondary into the distributor - also did the test of pulling out the coil to distributor wire and connect a know working sparkplug and ground it to the engine lift point ans still no spark.
6. checked engine Temp sensor for resistance - working ok
7. has no engine immobiliser

Is there anything I missed?

the car has been working fine and running great as I use it every day. I got home last August 19th 2014 in the evening and the next day it just cranks but from then on, no spark

would appreciate any help - i've been to the benzworld forum and the guys there have also been sending things to test but I'm hoping for more opinions from here as well

thanks
Glenn

[Frank Reiner]

Given that the EZL is believed good, and the coil is believed good, look for an open circuit in the wire from pin 16 on the EZL to the neg. terminal on the coil.