Idling Issue.

Car:1993 190e
Engine:2.3 (Supposedly - Is there a way to tell by vin?)

Ok, here is the problematic situation in a nutshell. This is my girlfriend's car, and last week it died on her. I was gone so she took it to a mechanic. When it was dead, the starter would turn and you could hear the cylinders hit but the engine would not start.

Mechanic's Diagnoses:It had been running for 15k+ miles with the wrong spark plugs, the plug wires were a little burnt up and looked like a rodent had chesed threw them, and the ignition coil was bad.

Mechanic's Efforts:New and correct spark plugs were put in, brand new plug wires were installed and a new ignition coil was added.

Now about 100 miles, and $560 U.S. later... the car is having an idling issue. When she comes to a light and stops it cuts out on her like it wants to die. When she picked the car up, the mechanic said the motor mounts were lose and would need to be replaced. I located the motormounts and one of them is completely lose not offering any support whatsoever. Could the vibrations from the motormounts cause the problems we are having? Or could it be something like a clogged fuel filter? Or maybe a timing issue? I wouldn't know how to resolve it if it was a timing issue, the distributor connects right to the cam. Any help or advice offered here would be great. Thanks in advance, I hope my post was imformative enough to help you help me. If any other information is needed please let me know and I will reply as promptly as I can.