Mercedes 260 se 1988 s class Starting problem.
 

Asking this question on behalf of a friend...He recently bought a mint 260 se that ran perfect...ticked over like a rolex! . One day he steam cleaned the engine with the car running....left it running for 20 minutes after to dry it out....then turned the car off and the next day he went to start the car and it wouldnt start!.

We started with the most obvious. got a new distributor cap and rotor arm...fitted these but no difference....we checked every spark plug individually and they all have a weak spark....We put a spark plug on the lead directly from the coil and theres a really strong spark.....but if you put all the spark plugs onto the leads at the same time theres no spark at all. Its really confused us and we dont know what to do next.

Any help will be much appreciated :) been working on this car for 3 days and no luck...