AMC Eagle Den Forum

The Mighty 258 => Emissions/Vacuum Systems => Topic started by: Brownc62 on December 09, 2019, 01:54:41 AM

Title: PCV valve routing looks wrong?
Post by: Brownc62 on December 09, 2019, 01:54:41 AM
Hello all, I’m an Eagle newbie and this is my first post. I’ve been gaining tons of knowledge from this website so far. I’m working on reviving an ‘82 wagon with the 258 and the first anomaly I have come across is the vacuum line routing to the PCV valve.

The valve has a “T” split with one line running to the back of the carb which is correct according to the vacuum diagram I found on here. The other end runs to the manifold and plugs into another “T” fitting with the power brakes. According to the diagram, this line should run into the “canister purge” instead.

My question is will this allow the PCV system to still work properly?  Is the system essentially just getting double the manifold vacuum drawn on it with this setup? Or is it canceling out vacuum and causing the system to not work at all? The engine does seem to have some blow by, so I’m curious if this is an indictor that it isn’t working properly.

Just some background info. The car has been sitting for almost 2 decades because the previous owner could not get it to run higher than an idle. I threw a new carb and fuel pump on which didn’t fix the issue. I then disconnected the catalytic converter and that ended up fixing the problem. Revs up great now. It was totally plugged up! Wondering if that has anything to do with a malfunctioning PCV system?

Thanks for any insight!
Title: Re: PCV valve routing looks wrong?
Post by: Still Pat on December 09, 2019, 10:11:28 AM
From what I recall, mine was the same on BlackBird. Don't recall looking at this one.
Title: Re: PCV valve routing looks wrong?
Post by: MIPS on December 09, 2019, 03:21:17 PM
Because both vacuum ports are manifold and basically pulling vacuum from the same point in the manifold you should not have an issue with the PCV in this configuration. I'm assuming you've had the charcoal canister deleted?

Vacuum routing on the T for the brake booster should also run to the cruise control, CTO switch, vacuum solenoid manifold for the secondary air and sol-vac systems and one of the vacuum switches.
Title: Re: PCV valve routing looks wrong?
Post by: Taylor on December 11, 2019, 09:07:51 AM
If you still have the factory bbd carburetor this might help.