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Re: [T3] Is this my FI problem? Hose routing & oil breather - long waffle!


>>>Hose from each rocker cover to twin fittings at 3 o'clock on the air 
filter
Hose from 7 o'clock on air filter to top of aux air regulator
Hose from aux air regulator to underneath of throttle body by butterfly
Hose from flat rear plate of throttle body to oil breather pipe vent
Dizzi vac and advance pipes from throttle body (I know these are ok)

Oil breather has only one cap, rather than two.<<<

You've got everything hooked up where it's supposed to go, but it's the 
wrong breather box that has you mixed up. The correct '72 breather box 
(with the two caps) has a nipple coming out of it (where you would connect 
to the line from the back of the IAD) that is actually a spring loaded 
valve (like a pcv valve)....this is what you are missing in your setup, so 
I believe you are just sucking in a large amount of crankcase air directly 
into the IAD since you have this line connected to a breather box that does 
not have this valve. The '72 system sucks in fumes into the IAD and burns 
them via this "pcv" valve, so it's kinda regulated. That is also why we 
have the breather ports on the heads (in order to provide fresh filtered 
air to the crankcase since we are causing negative pressure by sucking out 
air).
The breather box with just a nipple and no valve doesn't work like our '72 
crankcase vent system. These systems just connect to the air cleaner 
instead of the IAD....that way, crankcase pressures just push fumes into 
the air cleaner to be burned. Back in the day, cars had a blow-by pipe that 
went from the crankcase to atmosphere, which put fumes in the air. I 
believe the initial attempt to clean up pollutants was to put these fumes 
back to the air cleaner to be burned.....prob. a poor system which is prob. 
why a positive crankcase ventilation system was incorporated.

So, this is why Jim suggested 2 solutions.....either continue with the '72 
system by adding the correct box and valve, or block off the pre '72 
components and connect your current breather box to the air 
cleaner......either way will work.....good luck!

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