I have an 84, 244 and on my way to work this morning all of a sudden it jumped up to 3,000 RPM and the radio cut off for a second. When I pulled over to check it out the only thing out of the ordinary was oil leaking from the filler cap on top of the engine. I have no idea what is wrong and there was no warning but now I'm stuck at work without a car. Someone please help me out.

replace the filler cap seal, that should work! cost only a few dollars at the dealer!

Check all the vaccum lines and replace the oil cap seal but also check the Flame trap it might be clogged building up excess pressure in the crankcase.