Puul a spark plug, ground the body of it to the engine block, and crank. You should see a nice blue spark between the posts. If it is yellow, you have a weak spark. If you are just testing the wires, just grab a cheap plug from the store (~$1), gap to spec, and try that. If you have spark, time to check for fuel. If you have both, check you crank position sensor (if equiped).

__________________
1989 300E 144K