Hi,
My 89 300CE (96k miles) won't start (engine does crank!).
This happened after a few times of difficult starting and then finally after the car was parked for a week it didn't start at all.
It is not a fuel problem as far as I can tell (injectors spray fuel).

That leaves ignition! The spark plugs spark, but not sure if timing is right or the spark are strong enough. How can I verify either one on this car?

I have replaced plugs, distributor cap & rotor and ignition wires within last six month (or 6k miles).

Klaus Hermanns

Are you sure you have good fuel?

Is the cold start valve working?

If you have spark, and spray from the injectors, then there's not much left.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Good fuel - really don't know, but that has not changed, tank is 1/2 full or so - so was running on that fuel for at least 100 - 150 miles.
As for the cold start valve - not really sure. But when removing the spark plugs there is fuel smell (and injectors spray) - so no fuel is not the issue. If it wasa hard to start - then maybe.

I am wondering about three things (and I am sure there are others)
1) can somehow the timing be so far off that the engine won't start - and how could I verify on this car that the timing is off or not?

2) qaulity of spark - how does one identify a weak coil - where you get a sprak, but it is not hot enough. The coil resistances measures as per spec (with a multimeter). How else can I determine a weak coil?

3) Is it possible that the catalytic converter is clogged - how would one determine that?

Klaus