To much vacuum in crankcase

[HvacAl]

I have just rebuilt the top end of my wifes 1994 aerostar Van with a 4.0 . I had to replace 1 head and had the other rebuilt. this is because she overheated it. This is the problem I am having. the crankcase is under a large vacuum I had to pluged of all opening to the crankcase to get it to run. I think the problem is a intake gaskit. but not sure. Any sugestings would be very helpfull befor I start to tear it down again.

Thanks For your Help

Al

[wileys_farm]

Well if you plug all the vacuum lines and its still running its got to be sucking air from a source like your intake. Take some starting fluid and make a trip around your intake while the engine is running to listen for a rise in the RPM. This will determine if you have an intake leak or not.

wiley