sam44, when you say "new distributor" I take it you mean you replaced the distributor cap and rotor. Hopefully, you used Bosch parts. Check the Owner's Manual for the proper spark plugs and gap. You should not be using platinum spark plugs in that engine. What brand ignition wires did you install?

It seems you are using the term "crank" when you mean "start". "Cranking the engine" and "the engine turning over" mean the same thing. When you say "Turned off, would not crank" ... I take it to mean the engine would not start.

It's possible you need a new coil. How many miles are on this vehicle? It seems that the valve stem seals are shot, and the engine is burning oil. Your best bet is to have a MB-trained tech evaluate the condition of the engine and overall condition of this 27-year old vehicle. Most buyers opt for a PPI (pre-purchase inspection) by a MB-trained tech so you have a professional evaluation and ballpark estimate of necessary repairs before the purchase.

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Fred Hoelzle