Ok so the Holley that was on the car started to leak so I put this rebuilt Qjet on I bought here from a member. it's a '72 skylark mild build 350 with TA Stage 1 Aluminum intake. 4 speed car 1) Is this the correct fuel filter? It looks squished? Does anyone know the part number as its hard to measure since it's squished and on line there a re a few different sizes.. thanks 2) Looking for correct vacuum lines hookup and may have been incorrect from the old Holley. If i remember that are 2 different types of vacuum and don't know which has what or what is needed for each...The lines I have to work with on the car are: a) bottom of GS Ram air cleaner b) Charcoal canister c) Vacuum canister firewall d) PCV valve on intake I made some notes on the last 2 pics to see if the locations I want to use based on the size of the lines would be correct and numbered the vacuum spots on the carb Spot #1) charcoal canister? 2) Bottom of RAM AIR air cleaner? 3) Keep plugged 4) PCV valve on rear of intake? 5) should i plug or connect to #6? this is to the choke assembly i think so probably needs some sort of vacuum? 6) should i plug or connect to #5? 7) (rear of carb) Vacuum canister of firewall? 8) hook to #9? 9) Looks like it needs vacuum, should I hook to 8 or somewhere else? Thanks all, and sorry but if you can explain like I'm a second grader that also helps
That is the correct fuel filter. There is a spring that goes in with the filter, maybe yours is too long and the filter squishes when you tighten it down. https://quadrajetparts.com/spring-carburetor-fuel-filter-p-84.html https://quadrajetparts.com/long-paper-carburetor-fuel-filter-with-check-valve-p-82.html OK, there are 2 types of vacuum, manifold vacuum and ported vacuum. Manifold vacuum is sourced from BELOW the throttle blades. Ported is sourced from ABOVE the throttle blades. Manifold vacuum is constant anytime the engine is running, so if you unhook a manifold connection with the engine running, it will hiss loudly and you will have created a vacuum leak. Ported vacuum will be non existent at closed throttle idle, but increase rapidly as the throttle is opened. Both manifold and ported vacuum will be very close to if not ZERO at WOT. a) The vacuum hose from the air cleaner temperature sensor gets manifold vacuum. b) The charcoal canister is NOT a vacuum connection, it is more like a vent. It hooks up to your #3 on the front of the carburetor. c) The vacuum canister for the climate control gets manifold vacuum, usually right off the back middle of the Quadrajet carburetor. d) The PCV valve hose connects to the big 3/8" nipple on the front of the carburetor. Your #4. There is a special molded hose, http://www.taperformance.com/proddetail.asp?prod=TA_1240D OR, you can use plain 3/8" fuel line hose and loop it around the passenger side of the carburetor. These are pictures from the 1971 Buick Chassis Manual. The 7041540 is a 1971 Buick 455 carburetor. All of the outlets are labelled.
Thanks Larry. This helps a lot! Yes there is a spring in the filter housing... they had the spring in front of the filter close to the fuel line which didn't make sense so the filter wasn't sealing to the front of the filter housing... I moved the spring to the rear to push the filter into the fuel line housing..... I did forget about the distributor vacuum. I assume the vacuum advance for the distributor needs ported vacuum and should be hooked to #2 on the front which says ported vacuum nipple in pic 64-30? If so, here is what i would have: a) The vacuum hose from the air cleaner temperature sensor gets manifold vacuum. Hook to #1 in my pic which in diagram 64-32 says is full manifold vacuum. b) The charcoal canister is NOT a vacuum connection, it is more like a vent. It hooks up to your #3 on the front of the carburetor. DONE c) The vacuum canister for the climate control gets manifold vacuum, usually right off the back middle of the Quadrajet carburetor. DONE d) The PCV valve hose connects to the big 3/8" nipple on the front of the carburetor. Your #4. DONE e) This leaves distributor advance which needs ported vacuum and should be hooked to #2 on the front which says ported vacuum nipple in pic 64-30? Is this correct? Ports 5 & 6 get connected to each other on the front, correct? Ports 8 & 9 get connected to each other on the rear, correct? New pics show what i would do... Thanks again for all your help.
Yes, vacuum advance can be hooked to either manifold or ported, but for now, I would hook it to ported vacuum, that will be fine. YES, there should be small hoses connecting 5 and 6, and 8 and 9. Those should have been there from the get go. Did you remove them? If not, where did you get that carburetor? Also realize you are putting a 455 carburetor onto a 350. Might not be optimal.
Thanks. There were no hoses on 5/6 and 8/9 when i got it which i thought was odd. Here is where I bought it. http://www.v8buick.com/index.php?threads/1971-quadrajet.354166/ I originally bought it for a 455 I have but noticed a small leak on the Holley that was on my car. My 350 is pushing a little over 300 HP with flat top v6 pistons (pretty torquey) so I figured in '71 the 455s were about similar so though this might still work OK for my daily driver until I swap in the 455... any other suggestions to tune it? I'll might start another thread for that.... thanks again Larry..
Well, you can see the hose with a screw in it for the front choke pull off. The rear one is less important, but there should be a hose there as well. I find it odd to leave those hoses off after rebuilding a carburetor. A 455 carburetor has a bigger idle system than a 350 carburetor. That is the biggest difference. See how it works.
Nope, that's for the Climate Control vacuum storage container on the fire wall. Modulator line comes off the intake manifold. You could use that for the modulator, but that is not how it was stock.
@LARRY70GS Question about the #7 connection off the back of the carburetor for the climate control canister on the firewall...I have a dilemma, My trans modulator went to this port because someone removed my air conditioning. I am now putting my air conditioning back and need a place to connect the trans modulator. I noticed the plug on the top of my manifold for the trans modulator has been plugged up. No way to get whatever is in it out. Looks like a bolt was added and ground down at some point. So would it be better to add a Y on the back of the carburetor at the #7 port and connect both the climate control canister and trans modulator directly to the carburetor? Or would it be better to get a 3 way fitting for where the brake booster vacuum connects on the manifold and Y the connection for both the brake booster and trans modulator there? Thanks, Nick
Hey Larry, So I finally got my "new to me" 72 455 carburetor with a performance build. It doesn't have the secondary choke on it (no connection from 8 to 9 since 9 doesn't exist per the picture). Since I don't have the #9 secondary choke pulloff, can I connect my transmission modulator to number 8 port on the back of the carburetor? Initially I was going to Tee off the AC vacuum canister. Thanks again and happy 4th, Nick
The modulator line comes off the intake manifold. Why can't you put it there? Edit, I looked back a few posts. Yes, you can put it there.
