tlowc34

Hello Everyone,

I'm really close to starting my refreshed 394 for the first time. The one issue I need to solve is how to match up all of the fuel and vacuum lines in the underhood area (I have the service manual that show the HVAC routing, so I'm all set there).

Here are the specifics on the Olds:
1962 Oldsmobile
Dynamic 88 Holiday Hardtop Coupe
394 2V w/Slim Jim w/Rock Auto Rebuilt Carb

This is what I have so far:
Fuel Pump Fuel Side IN > 3/8" Hose to Fuel Tank
Fuel Pump Fuel Side OUT > 3/8" Steel Line to Fuel Filter IN
Fuel Filter Out > 3/8" Steel/Rubber/Steel line to Carburetor
1/4" Hose to Fuel Tank > Vapor Port on Fuel Filter

Then it all starts to be guess work. These are the odd ends left out:
1. Rubber hose that attached to the brass choke port on the bottom side of the intake manifold.
2. Teeny-tiny (1/16"?) vacuum port on the LH side of Carb
3. Hidden (1/4") double flared port on the RH side of Carb tucked sort of up and under the bowl. You have to tilt the carb to see it.
4. 'Wiper' side of the Vacuum Side of the Fuel Pump
5. 'Engine' side of the Vacuum Side of the Fuel Pump
6. Vacuum advance on Distributor
7. Hard Steel Line (1/4" Inverted Flare) that comes off the same brass vacuum distribution block on the backside of the carb that the PCV valve is threaded into and attaches to the brake booster hose

Any help or pictures of a similar setup would be great. I'm totally lost here. I don't want to guess and check either since I repainted the intake and would hate to have gasoline pouring all over it!

Thanks

therobski

This is my first early big car, bought it last week. Been in climate controlled storage and 90% original. I can help you when the car gets shipped to Dallas in a few weeks. If it was an early A-body 64 up no problem I could fix you up.

Charlie Jones

Your car has electric wipers. If the fuel pump has a "vacuum" side then it has the wrong pump, probably from an older model.
If it still works OK, then cool. You don't need to connect anything to the vacuum side.
Vacuum advance on the distributor should connect to the teeny port on the carb.
The heater system should be connected to manifold vacuum also.

bob p

> If the fuel pump has a "vacuum" side then it has the wrong pump,
> probably from an older model.

I disagree. Vacuum assisted fuel pumps were used on some 1962 88. My Super 88's fuel pump is the vacuum assisted type and the engine is bone-stock.

Here's what the Olds 1961 Service manual has to say about it, Engine section, page 8-35:

tlowc34 -- It's raining today, so I can't go out and trace lines or take pictures. Do you have a copy of the 1961 service manual? If not, I highly recommend looking for one. Mine was money well spent.

bob p

Hey therobski -- just noticed something about your car...

Where does that crankcase ventilation line (originating in the middle of your right side valve cover) go? Did somebody hook a PCV valve up to your intake manifold?



On my car the crankcase breather is a solid metal pipe that dumps any overflow oil down onto the pavement!

tlowc34

Actually, the Dual Action pump is correct for 62 Oldsmobiles according to both the service manuals and my experience. Both the super 88 and dynamic 88 that I have came with the Dual Action pumps. In 1963 they switched the timing cover to aluminum, changed front motor mount to attach to the bottom of that cover, and moved the fuel filter down to the side of the 'pump' only fuel pump.

The PCV hose shown is similar to my setup. The connector at the valve cover isn't actually a pcv. The pcv is further upstream screwed into a brass block that is connected to the back of the bottom carb plate along with the brake booster and random vacuum line that I don't know where it goes to?

Thank you for the help on the distributor vacuum advance. With that solved I'm down to figuring out the following:

1. Rubber hose that attached to the brass choke port on the bottom side of the intake manifold.
3. Hidden (1/4") double flared port on the RH side of Carb tucked sort of up and under the bowl. You have to tilt the carb to see it. (I think this isn't connected to anything.
4. 'Wiper' side of the Vacuum Side of the Fuel Pump
5. 'Engine' side of the Vacuum Side of the Fuel Pump
7. Hard Steel Line (1/4" Inverted Flare) that comes off the same brass vacuum distribution block on the backside of the carb that the PCV valve is threaded into and attaches to the brake booster hose

Kahuna

Hey Bob,

You must still have the original down draft tube on your car. You can install a PCV valve to the intake manifold (or the base of the carb with brass T-connection) and recycle unburned blow-by gases back into the engine. I did this on my car ('62 Dynamic 88) a few years ago. Saves fuel and no more nasty fuel/exhaust smells coming from the engine...not to mention better for the environment.

Bought my PCV valve from RockAuto.com. Just spec it for 1962 Starfire. You'll also need a valve cover grommet, grommet-to-hose connector and proper-sized hose.

therobski

Yes the previous owner used a T-fitting and routed a PVC valve line to the back of the carburetor. BUT, this guy disconnected all the other vacuum lines including no more power brakes. Kahuna did you route your PVC line into a port on the intake manifold? If so I rather do that, because I think some of the blow-by could be sucked into the PW booster canister located on the driver side lower wheel well. ( I have to take the hood off and re-install mine)?? And that maybe why the other guy disconnected all the other vacuum lines that I also am trying to figure out how to put back together. I do have the 61 and 62 shop manuals. Looks like 'm missing a small barrel shaped vacuum canisters that sit on the firewall. I will look today and see what my fuel pump looks like. If you look at my picture, the passenger side fender wheel show two vacuum lines plugged??

therobski

(Two types of fuel pumps are used. Cars without deluxe heater or air conditioning use a fuel pump without a vacuum booster. ) I looked at mine, at least from the underside ( cars up on a lift got starter out) and could not see any vacuum lines or ports unless they are on top the fuel pump. I think the two plugged lines you see in the picture on the pass side wheel well go to a windshield washer jar that is missing.

therobski

I'm going to re-route the PVC valve to an air-cleaner I recently built. Pictured is a dual snorkel air-cleaner I made out of two 65 Starfire Lids. The pass side snorkel has a provision to run a tube from the PVC valve. I built for my 64 F-85 build but I did think about hood clearance until it was finished. It should look cool. Then I can hook the vacuum booster back up with out worrying if the brake booster and canister will suck up oil. Fits perfect on the 62 base.

bob p

Yes. I have one of these:



This sounds like an interesting update -- especially to get rid of some of the blow-by smell. Like therobski, I'm going to have to do some study to figure out exactly how to hook it up so that I don't get blow-by where I don't want it.

Kahuna

Ok, a few things:

1) Yes, I connected the PCV valve to the base of the carb with a T-connection. On 4-bbl models you can install a base plate underneath the carb that has a dedicated vacuum port but they are very difficult to find. I have a 2-bbl carb, so I had to use the T-connection method.

2) I do have power brakes (was originally a manual brake car) and I have the proper teardrop shaped vacuum (reservoir) canister in the driver's side fender well (yes, the hood had to be removed to install it).

3) To avoid the blow-by gases from backing up into the brake booster or vacuum reservoir canister, I simply installed a $15 charcoal filter (looks like an inline fuel filter) between the carb and the inline check valve. Works great!

4) If you use the air cleaner method (see attached photo - not my car), be advised that the tube which connects from the air cleaner to the (canister type) PCV valve mounted on the (passenger side) engine valve cover is only meant to provide a clean vacuum line (large dia. tube) to actuate the opening and closing of the valve itself. You still have to route the blow-by gases (small dia. tube) to the carb or intake manifold. You don't want to route the gases directly to the air cleaner...the filter will clog up in no time.

Hope this helps.

P.S. Nice work on the air cleaner, therobski!

therobski

Kahuna that's great info, thanks. I noticed in the picture a round looking canister behind the pass valve cover, is that a vacuum reservoir for the heater? On other 62 pictures I've seen one above the PB booster

Kahuna

No, there wouldn’t be any need for reserve vacuum for the heater once the engine is off. This canister is more likely used for an accessory option, such as a vacuum trunk release.

therobski

Nice, appreciate your help.

dlh61olds

The teeny tiny port on the left front of the carb probably is to the dashpot

therobski

Nice, found it and the hose is dry out will change it! Thanks Kahuna

therobski

Update guys check out the picture of the fuel pump, is that the vacuum line that's plugged? Except for the distributor why is everything that needs vacuum plugged on this car, its jacked up!

bob p

Your car uses a 2-bbl carb right? I'm going to be limited in my ability to help you, because I have a similar problem with mystery vacuum lines on my 4GC equipped car. Maybe we can both get the answers we need if someone else can help us. Here's a picture of my car after it sat for 20 years -- right before I rebuilt the carb:



On my car the solid metal line at the top of the fuel pump (the one closer to the engine block and connected on your car) is indicated in this photo with a RED trace. It tees into the main vacuum line on the back of the carb; the brake booster vacuum line also connects into this same tee on the back of the carb at the big Red Arrow. So far so good.

On my car the second terminal at the top of the fuel pump (the one that is capped on your fuel pump) is indeed a vacuum line, not a fuel return line as mentioned in your PM. On my car It connects to a long piece of soft vacuum tubing that goes back toward the firewall. It is indicated in this photo with a BLUE trace. It ends near the firewall and is flapping in the breeze, not connected to anything.

I have a second disconnected vacuum line that is not connected to anything. It's indicated by a GREEN trace. This line comes off of the right side of the carb, tees off to another hard line that goes to the choke pull off on the left side of the carb, and connects to a soft line that goes toward the firewall. Green trace.

Back at the firewall I have two loose vacuum lines and two loose vacuum connectors. I'm not sure which goes to which. One of the connectors in need of a vacuum line is the distributor's vacuum advance. The other connector is on a vacuum operated valve on a water line between the heater core and the rear of the engine block. Obviously, either the GREEN or BLUE vacuum line is supposed to go to the distributor's vacuum advance and the other is supposed to go to the fuel pump, which doesn't really make sense to me.

The fuel pump gets vacuum from the rear of the carb using the solid metal RED line. The second vacuum line on the fuel pump appears to be there to distribute vacuum to an accessory, perhaps to the heater core's vacuum switch. It makes no sense to me that they would have routed heater vacuum off of the fuel pump, so if anyone can explain if this is right or wrong, and why they did it this way, I'd appreciate the explanation.

The heavier GREEN line looks like it should be going from the right side of the carb directly to the distributor's vacuum advance, but I'm not sure about that. I'm still trying to determine if the GREEN line corresponds to ported vacuum or manifold vacuum. If so, the it's the only way this would make sense to me. Unfortunately, I'm having trouble finding good documentation on this.

I'm operating under the assumption that:
RED LINE = Manifold Vacuum
BLUE LINE = take-off of manifold vacuum from fuel pump
GREEN LINE = ported vacuum

Can anyone confirm or refute this? thanks!

bob p

Rob, where does your distributor's vacuum advance line hook up?

therobski

The distributor vacuum line is on correct. Goes from the distributor to a small port in the front of the 2bl carb. On my fuel pump I wonder where the plugged line goes? HMM I will look into the 61 62 shop manuals and see what I can find there.

therobski

HMM, looks like so far your red line is my blue line in the picture. Your green line may need to go to the distributor, like my green line. Your blue line and my plugged line from the fuel pump go nowhere ( not yet anyway). At least its a start!

bob p

Thanks for posting those pics.

Your Blue / my Red is definitely full manifold vacuum, and it makes sense that that should go to the fuel pump.

Our Green would make sense going to the distributor's vacuum advance unit if it is ported vacuum.

Still not quite sure why the fuel pump has that extra line, which is disconnected at the far end on mine and plugged on yours. (Unless I can figure out what it's supposed to go to, I'd be better of plugging mine than leaving a leak.)

Prior to posting my thoughts in this thread I had reviewed the 1961/62 service manuals, the 2 main Rochester carb books (which have purged the 4GC information from the print editions), and my thick folder of technical documentation on rebuilding the 4GC. The answer isn't to be found in any of those places. All of the conclusions I've drawn have been based on how a QJet is supposed to work, and applying those principles to the older carbs.

Have you had a chance to look at the 61/62 Olds Service Manuals? They didn't help me. I was surprised that they don't address where that extra vacuum line on the fuel pump is supposed to go. The manuals don't have a comprehensive diagram of the vacuum system on these cars. Sure, there's a partial diagram of the HVAC related portion of the vacuum circuits in the HVAC chapters, but it doesn't answer our questions. the vacuum system on these cars is just not well documented.

This is one of those situations where the documentation just does not exist, and we really need someone who is familiar with this car, or the old style vacuum-assisted fuel pumps, to speak up.

Larry/car

I got an original car that has not been molested! Ok let's start with the main vacuum source; rear carburetor base has about 3/8 vacuum line that goes aft to the power brake master cylinder via check valve than to the vacuum tank. There is a T fitting just aft of the carburetor and that steel line goes to the top left side of the fuel pump. The top right side has the rubber vacuum line that is routed via top of the right rocker cover to the firewall (firewall cavity about 16 inches by 6 inches 5 or 6 inches deep). The right side of the cavity has a rubber grommet with four holes, that is where the line is routed along with the vacuum line for the heater water valve and heater air valve on the heater air box. [also heater electric wiring]. You will have to remove the grommet to feed the hoses through. Take your time, mine removed without to much difficulty. Under the dash look for a T fitting with a vacuum line going to each push button control unit. That is your common vacuum source. When everyone has gotten this far let me know and we will work the system from there. Spigetti city, need specific questions??

Larry/car

Green line is the vacuum advance.

Larry/car

Red line is vacuum line to fuel pump.

Larry/car

Blue line is main vacuum line to environmental control units under instrument panel.

Larry/car

Questions?

bob p

Thanks for posting. Basically that confirms what I thought should be the plumbing arrangement. I still have a couple of questions though --

1. Is the green line ported vacuum? I know that if it's vacuum advance for the distributor then it should be ported vacuum, but I haven't been able to find the 4GC tech info to confirm this.

2. I'm still unclear on where that blue line is supposed to go as it approaches the firewall. It's definitely not long enough to reach the firewall, or to go to the dash -- it's only long enough to reach a vacuum operated valve on a water line between the heater core and the rear of the engine block. It's definitely not long enough to go through the firewall and reach the dash.

Different cars with standard/deluxe heaters reportedly have different vacuum arrangements. I wonder if that's what we're looking at here.

My car is also "unmolested", in that I'm it's second owner, though I can't make any claims that would assure that somebody didn't bugger up the vacuum system in the 30 years before I owned it. That's a long time...

therobski

BobP mine is 2 bl. One large port on the back of the carb is like the 4-barrel? And no wonder my heater and ventilation system does not work the line coming of the fuel pump is plugged. I do not see any ports on the intake manifold itself to work with. I will mess with it tomorrow and if I can fix some things I will post it.

bob p

yes, my 4GC has the main vacuum for mainfold vacuum on the back of the carb, just like your 2BBL. it's denoted by the big red arrow in my pic.

I'm not sure where my blue line could possibly connect if it doesn't go to the vac port on the heater valve. since i'm using the car summer only, i'm giving some thought to converting my fuel pump to be plugged like yours!

Larry/car

Not sure what you mean about ported vacuum? Never had to work on that system. Your blue line has been cut off. It definitely goes though the firewall via a split four hole grommet located in the cavity behind the distributor. It then connects to a T fitting sharing imput vacuum to the heater and summer ventilation control units. Crawl under the dash, see if you can find that T fitting. Look above the steering column. If you can't find it (was removed) I can draw diagrams and take pictures to rebuild your system. Have fun! {original type vacuum is available, is 65 inches long}.

Larry/car

photo2_zpsca56355a.jpg This is the T fitting under dash where vacuum source from engine connects

Larry/car

photo3_zps65660342.jpg The firewall grommet where three vacuum hoses pass through (engine fuel pump, heater water control valve, valve air source).

Larry/car

photo4_zpsb682c185.jpg You can see vacuum line on top of right rocker cover routing to firewall. Also the heater water control valve is located just aft top of rocker cover under sparkplug wires, that line also goes through firewall. The forward hose bracket at forward rocker cover bolt clamped my hose shut causing system to not operate (with new hose everything works as it should). Trace the hose aft along rocker cover top edge follow it just behind the heater water control valve to firewall grommet.photo4_zps5e702277.jpg

Larry/car

photo1_zps6bc5f2c3.jpg View of water control valve and vacuum line routing to firewall.

therobski

Larry/car is that a check valve in picture 2? Shows large vacumm tube coming off the carb to the master cylinder and on its way to the canister. Also I just noticed there another small vauum port up in front of the carb. I need to check on these things when I get home tomorrow. THANKS!

therobski

You have a T fitting in front of the carb, where does that line go that shows it going across and down the passenger side valve cover?

Larry/car

Yes that is a check valve. The line in question, upper valve lub system. Oil is sucked into the manifold to lube the valve stems (something like that). Evidently the 1954 Chevrolet had sticking valve problems and this suposingly eliminated this problem. The system migrated to a 1957 V8 Bel Air and finally to the Oldsmobile where it currently resides. This car was first my grandfather's purchased new in August 1961. I will post a picture of the device, never have I seen another like it.photo1_zps438e5d1d.jpg

Larry/car

Heater thermostat vacuum line goes through firewall to heater water control valve. Heater mechanically controlled via slide on control unit. Be careful this thermostat is available marked down to a fortune. photo3_zpsdbb4608d.jpg