I have never heard of your problem, but I can tell you that it is a problem. The valve cover breather is supposed to let built up pressure within the engine escape. With your problem of it sucking in AND having a smoother idle, it sounds as if un-metered air is making its way into the combustion chamber. Im not sure what the problem would be though, you will have to do some investigating to figure out the problem.

My first thought would be to give the car a cylinder leak test and determine if the valves are leaking and which one. Based on your symptoms, it sounds as is an intake valve seal is leaking enough to let air by (if possible).

Let us know what you find.

I have never heard of your problem, but I can tell you that it is a problem. The valve cover breather is supposed to let built up pressure within the engine escape. With your problem of it sucking in AND having a smoother idle, it sounds as if un-metered air is making its way into the combustion chamber. Im not sure what the problem would be though, you will have to do some investigating to figure out the problem.

My first thought would be to give the car a cylinder leak test and determine if the valves are leaking and which one. Based on your symptoms, it sounds as is an intake valve seal is leaking enough to let air by (if possible).

Let us know what you find.

Yeah, somehow your intake is getting attached to your crankcase!

But if it was valve guides, you'd have an oil burner...

If it's serious suction, I think ya gotta start looking at every hose...
I'm not good with tii's, but I don't remember any easy way for this to happen....


t
_________________
I have a car disease. There is no cure.
I'm not even managing the symptoms very well...

Toby is right about everything except Chickens, GIUBOS and Mt. St Helens.

That port off of your valve cover is a breather designed to feed the blowby fumes back into the intake and NOT the other way around. I can't visualize your setup and expect Chicken-Toby is right that you are drawing vacuum from manifold pressure. THis aint something you detect with propane, this sounds more like a hose misfitted or something that needs to be capped or rerouted.

I also wonder whether you are not drawing vacuum sourced from the crankcase. As strange as it seems, I recall working on a D-Jetted E9 which wouldn't run well due to a dip stick that was not seated properly. In that case, if I recall correctly, we by bypassed the source of the vacuum which was at or near the throttle body by running a down draft tube and capping the port at or near the throttle body. There was a threaded port at the side of the case that may have been tapped to connect a sensor of sometype. It was left with a weird petcock that was partially open and resulted in a pressure differential. It wouldn't surprise me if you did not have a similar odd situation, but not having an 02 anywhere near me, I am unable to think of a specific port. In any event, I think the cure should be obvious if you go eliminate all the obvious suspect sources.

HTH

Hey, I did NOT (bwaaak) throw that chicken into Mt. St. Helens.

It was pretty tasty, though.

Guibo. Guibo guibo. Kugelfischer Bosch ATE Sachs Bosch.

t
_________________
I have a car disease. There is no cure.
I'm not even managing the symptoms very well...

TobyB wrote:

Hey, I did NOT (bwaaak) throw that chicken into Mt. St. Helens. It was pretty tasty, though. Guibo. Guibo guibo. Kugelfischer Bosch ATE Sachs Bosch. t

Im so confused!
haha

The guibo is part of the transmission, how would it affect the vacuum?
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1974 tii "Mr. T"