92 300E 3.0 - No Spark - Need Troubleshooting Help
 

I was driving my car on the freeway yesterday when it suddenly quit, as if the ignition switch were turned off. No sputtering or hesitations, just on one second and off the next. There appears to be no spark. The last time this happened (on my 86 300E) the EZL ignition module (on the left inner fender well) died.

Can anyone help me with some sort of trouble shooting procedure to rule out the various ignition parts that could've gone bad?

I saved the good ignition module from the '86 when it was totaled. Should I start by trying that, or are there other, more common failure modes I should look at first?

Thanks for any help.

Gary

First check to see if there is a dwell signal to the coil.

If not check to see if the crank sensor is generating A/C voltage (at least 0.5V) while operating the starter.

Problem solved! Turned out that the dist. rotor adaptor shaft snapped off at the base of the shaft. No indication as to why. It looks like the part may made of sintered metal, but I don't know if that contributed to the failure. Anyone else ever seen this part fail like this? I'm replacing the adaptor, rotor, cap, plugs and plug wires as they were all fairly long in the tooth.