1970 280sl:
put the rebuild distrubutor in and turns out the old cap didnt fit. so i got the right one and it would turn and turn without any firing. Put the old distrubutor and the same thing happned. swapped them out a few times throughout the day and I accidentally did something that got the car running. I was checking to see if i was getting spark to the dist cap and it turned over! when i hold the wire 1/2 inch above the cap, the spark jumps into the cap (you can see it) and runs like a charm.
I tried this with both distributors and same thing. My only guess is that its the coil, but WHY?

But can it be? I'm getting sparks, so coil is working?
Thanks for reading

What you are doing is establishing a booster gap. This becomes the highest form of resistance in the circuit and takes the spark energy and changes it. The conditions that exist, most likely fouled plugs or rich mixture have made the spark required very low voltage (with a longer duration to disapate the energy). By creating a booster gap you have artificially upped the spark voltage (shorter duration) probably on that car to around 25kv (it was probably around 5kv if left to the conditions that existed).

The extra spark voltage is overcoming the mixture or plug problem.

__________________
Steve Brotherton
Continental Imports
Gainesville FL
Bosch Master, ASE Master, L1
33 years MB technician

you were right! (obviously). all my plugs were fouled. I just put in a new set of bosch platinums in, but I'm worried the mixture is too rich and its a matter of time before the new ones get messed up.
I do i control the mixture on the FI?

one more question: The new (rebuilt) distributor is making me crazy! I set the point and the car will start (but run like crap, as previousy posted), and then I'll check the point again and it wontbe set again. Why does the stupid thing kep moving?