engine question
 

hi.. i have a 1993 mercedes 300se 6cyl and the engine is missing an shaking my question is. how can i tell if it has a bad spark plug wire or a stuck valve i change the plugs i had some in the garage i want to check it myself before i take it to the shop thanks for the help.

You can read the fault codes on the 38 pin diagnostic connector, in particular pins 4, 17 and 19.

You can also check the wires with an ohm meter.

I don't think that car has 3 coils, i.e. 104.990.

Good correction.

140 chassis 104...no DIS/.992