Emission/vacuum questions.
Thread Starter
Instructor
Joined: Apr 2006
Posts: 105
Likes: 0
From: Knoxville TN
Emission/vacuum questions.
In my quest to get my 79 running I swapped my quadrajet for a edelbrock 600cfm carb. I am running this on my stock intake. I have already eliminated the EGR and was told I should eliminate the other vacuum lines that are emission lines IE vapor canister and efe lines. I am leaving the rear port on the maniflod since it controls the lights and a tranny vacuum line. My question is are there any of the front thermal ports that are needed. I replaced the stock thermostat gooseneck with one without holes for the ports and plan on capping the third front port that sets directly in the manifold. In pulling the lines off of what I assume to be the vapor canister I noticed there was a 3/8 soft hose that ran back into a hard line that went toward the back of the car I couldnt track it down so I was worried about where it went and what it does. Also there are two hard lines that come up out of a plate on the passenger's side of the intake and ran into the quadrajet. Is it ok to cap these and what is the best way to do it, like is there a ready made plate for it like the ones they make to cap the egr valve? Any help would be appreciated.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
that line is te fuel tank evap recovery line. I would keep all the vapor canister stuff if it was me. It does a pretty good job of policing up the fuel vapor that evaporates out of a hot engine/carb and keeps them out of the garage. It also does not cost any horsepower, isn't complicated and is a green friendly thing to do. But if your dead set on killing ozone yes you can cap them off. If this car is an auto the other lines (one anyway) goes to the Vac MOd on the tranny, you will need that. I would have to take a look to see what the other one is.
Melting Slicks
Joined: Mar 2006
Posts: 2,465
Likes: 0
From: Orange Park Fl
If you cap off the line from the canister that goes back to the gas tank, you will need a vented gas cap, or cap the line with one of those little air filters you can buy at Autozone. Otherwise, the gas tank will pressurize and let out otherworldly moaning sounds every few minutes. God bless, Sensei
Thread Starter
Instructor
Joined: Apr 2006
Posts: 105
Likes: 0
From: Knoxville TN
In order to keep the canister functioning I would have to have two 3/8 hoses running into my edelbrock but it only has one fitting and I used it for the pcv valve would i just install a "t" fitting and run both large hoses through the same port in the carb? Also do all three of the ported vacuum fittings operate the same meaning could you theoretically swap the lines on them around without any issues?
