Experts,Please help, starting problem 500 sel
 

1982 126 500 sel euro car, all original.
I have been having a starting problem for about 2 months. The car cranks strong but will not start and run, this is most common on first start in the AM but could happen after its been run then shut off for a couple of hours. Or it could start fine first try. I did pull the coil wire at the distributor and it had good spark, and started right up after I plugged the coil wire back in. Yesterday I did the same thing and the car started while the coil wire was unplugged and spark was jumping to the cap, I shut off the car, plugged it back in and it wouldnt start... I kept trying the starter and it eventually did start. The only other symptom is upon starting the exhaust seems just the slightest bit black, like a too rich condition. Other observations.... may happen when fuel is low, (new pump installed 8 mo ago) but not nesessarily, seems to catch and start if starter is applied in short bursts, (2-3 seconds vs 10-15 seconds)not long cranking sessions.
Otherwise the performance is up to par, exhibits no unusual symptoms or actions. I am 5 hrs from any MBZ dealer or bonified foreign car repair facility. I am sorry for the lenght of the post but am genuinely at a loss in diagnosing this matter. Scott

someone?

Pull and replace your plugs. Them act of starting the car with the coil wire held at a gap is a trick used to increase firing voltages and fire a fouled plug.

Based on your results I guess you have a rich mixture and fouled plugs.

Thanks Steve I`ll try that on Monday and let you know how it goes...Scott

anyone else have a guess?