I have a 91 740 B230FT engine. There is excessive amount of pressure coming from oil filler cap blowing oil over the top of the engine. Also having trouble controling the engine idle. I havereduced the idle, but raises backup over time. I need advice on what could be the problems.

 

Oil blow by is probably caused by PCV. Search the forum. You'll find info on repair. Not sure about the idling problem.