'73 PCV valve leak, High idle even after throttle body rebuild Options

[chmillman]

Hi all,

So still working on the FI, have gotten a lot of stuff fixed. But, despite rebuilding the throttle body to fix an air leak around the worn shaft, the idle is still too high even with the screw turned all the way in. My FI guy did some research and found that the PCV valve is leaking. He put a constrictor clamp on the hose from the PCV valve to the intake manifold and adjusting that brought the idle down.

Apparently the configuration on the '73-'74 motors was to route the output hose of the PCV valve directly to the intiake manifold, whereas before/after the hose just went to the air cleaner. So if there is a leak in the system, it can cause idle problems - I guess that's why they changed it...?

Anyway I found this 5 year old thread here:

http://www.914world.com/bbs2/index.php?sho...c=347986&hl

Again apparently, since the original PCV valve is NLA, there was a suggestion that it be replaced with a Toyota part - haven't checked if it is still available. Is that still the current thinking? Having read the thread, I am a bit worried about the potential overpressure/underpressure problems it could cause...

Other possibility I guess would be to eliminate the PCV valve entirely and pipe the hose from the oil filler neck directly back to the air cleaner, and plug original hose entry into the intake manifold ?

Any other suggestions? TIA!