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