Engine Problem

[J&MStang]

Originally posted by David Fulford
You may be right, but my car definitely runs less rich at idle like he told me it would. Technically, it still has a breather but from the breather, a hose runs to the port on the underside of the air cleaner. It made a difference in my car. The guy I got the info from runs the only speed shop in my city and has built motors for everybody I know. That doesn't make him a genius but I trust him. Have a good one.

I understand, yours is a "closed" PCV system as opposed to the "open" PCV system I described (with just a breather cap on the left bank). The closed type like you have gets its input air from inside the air cleaner periphery. The advantage of this is if any gases escape from the breather, they are gobbled by the carburetor. In the "open" case these reverse flow gases are not burned rather escape to the atmosphere. The closed system is better environmentally and could cause the engine to run a tad bit richer under certain conditions. Your system is the "preferred" system but is not required by law on classic cars. The "open" system is simpler to implement.