Hi,

I Don't find in forum the exact size of vaccum tubes on quadrajet carb, mine are old and i want to change them.
Can i change them easily , means deplug/replug for all of them ?

Thanks

 

Hi, i saerch again and found some informations like this : 5/32 ( more or less 4mm) and 7/32 (3mm).
As precedent owners of my cars made some modifications i'm surprised to find many adaptators on the hose lines.
Is it normal that you start with a big diameter on a side, then need an adaptator to connect on the other side ?


hose diameter adaptator


I founded one on the back ofthe carburator that goes down the motor that was burned !!!

vacuum hose burned
had to make an adjustment like this


I also need help because i see one part is broken :


See blue circle broken connector

What is the name and part number of this item and where shall it be connected ?

Best Regards

 

The line in the 1st photo looks factory to me. They did in fact use different size rubber hose nipples on opposite ends of some of those nylon hard lines. Here in the US you can go to the parts store and buy various sizes of that nylon line and various ends in a range of sizes for it; straight ones like that, 90° ones, etc.

7/32" is closer to 5.5mm. ¼" (8/32") is 6.3mm. 9/32" is very close to 7mm, close enough that both size sockets can usually be used on either size screw.

The aquarium tubing in the 2nd photo is … inexcusable. Hard to believe someone could be that ignorant. But I guess there's one in every crowd.

The 3rd photo shows the connection that should go to the MAP sensor, which is (was originally) on the left side of the car near the brake booster. What is it connected to now? How is the connection to the MAP sensor being made?

Not sure about the 4th photo; a picture from farther away, where we could see where the line that's still there is going, would help. I don't think I've ever seen a check valve with 2 ports on the side like that one going to the pink vacuum switch, either. It looks like your entire vacuum system might have been "customized" a bit too much. Might be a good idea to look in the "vacuum line diagrams" post on this site, and find the closest one you can for your car, and follow it.

 

Keep in mind 'export' cars often have minor differences in emissions and computer controls, etc. The vacuum lines on a domestic market diagram may be different from what you'd find on an export.

 

True dat... however when you see aquarium tubing used as vacuum line and Teflon tape on thermal vacuum switches, it's virtually certain that SOMEONE has had his d***-skinners in there somewhere somehow sometime, and it probably needs to be de-sodomized. Or at the very least, checked over carefully for additional hidden sodomy.

 

OK clear , happy to see it's factory look like !!!

It's not an ignorant, as i discovered i was missing the relay in the convenience box and chocke shutter blocked with a string , i have to check everything now :

It was the aquarium tube ! it's reconnected now ! Can you tell me the use (or trouble it makes me) for this vacuum tube not connecter ?

Find below a bigger picture, i note 1 ; 2 ; 3 ;4 for the pink , i dont understand the idea to double the tubes then to go to 2 diferents places on carb !!! perhaps it would be better to go straight each one with it's own vacuum tube ?
And for the other one destroyed , and also yes with teflon, i not it's connection ion blue on front of carb.
What is the part number or name of this item for beign able to order a new one, as i there is a "hole" going to nowhere !

 

OK, now some of it makes more sense.

The thing marked #4 is the vacuum advance canister. Its function is to advance the timing when the RPMs are relatively high and the load is low; in other words, cruising on the highway. The extra advance makes the engine run cooler, get better gas mileage, and feel more responsive to small throttle movements. The check valve and lines 1 & 2 cause something about it to change at some temperature; not sure what exactly it does, or what temperature, but at least it makes more sense. #3 is the usual port on the carb that the vacuum advance is connected to. It's slightly above the throttle blades, such that at idle it's not exposed to vacuum, but if the throttle is open somewhat as it would be during cruising, it gets vacuum.

The connection to the EGR valve (large round thing behind the carb) doesn't look right. There's another port on the carb, similar to the one for vacuum advance, that ordinarily feeds it. There's not usually a "T" connection in that line. Something is not hooked up right down in there somewhere but I can't see where all the lines go.

Connection #1 is hard vacuum; it has vac whenever the engine is running.

Your car won't have a MAP sensor because it isn't computer-controlled. That means the connection on the rear of the carb, which also is full-time vacuum, should go to the air cleaner.

The thermal vacuum switch connected to line 1 is probably the one for the EFE valve. That valve is in the exhaust, where the pipe connects to the right side exhaust manifold. It closes when cold due to a thermostatic spring much like the choke, and also vacuum from the thermal vacuum switch pulls it closed; but when the coolant temp reaches a certain point, that thermal switch should open and stop feeding vacuum to that valve, which lets it open. When closed it routes the right side exhaust through the center of the head, through the intake manifold under the carb, and over to the center of the left head and onward to the exhaust on that side. Its purpose is to help the engine warm up faster as far as how it runs: those parts of the intake will get warm MUCH faster than waiting for the whole engine to warm up. That whole system is not hooked up right, obviously.

Your upper radiator hose looks like it will burst any time now, right next to the hose clamp. I'd suggest replacing that before you try to drive this thing anywhere.

The #2 spark plug wire is out of its loom and not routed correctly. You should put it where it belongs to keep it out of harm's way.

Looks like this poor car has DEFINITELY had an ignorant owner before you got it.

Where does the red hose go?

 

I Don't see what item you mean, behind the carb, there is cap where arrives all the sparks cables. What T are you talking about ? can you make a mark on my picture ?

It's the tube at Bottom middle behing carb where was the aquarium tube, and goes to the MAP as you said.

As you are regulary talking about temperature, note that my motor temperature is a little too high when driving…. perhaps something related to those troubles ?....

 

Behind and beside the carb, a metal round object about 4" diameter with a single vacuum line going to it.

I am asking about the other end.

No it can't possibly go to the MAP sensor. Your car doesn't have a MAP sensor. It isn't computer controlled, which is what the MAP sensor is part of.

I have been talking about it regularly because so many of the parts you're trying to debug, are related to it. Not so much that they affect it, like they would make it run hot or cool; but rather, they are affected by it. They measure the engine temp, in particular as it warms up when started cold, and do something in response.

 

Thre other end of red tube goes here (Bottom passager side)


other end of vacuum tube , other en is behind carb middle at it's base


And you see on this second picture the other side of red tube (that i surligned as there is an adaptator on a black tube after) and in blue rectlangle the other part you'r talking about ?

 

The red hose is going to the EFE valve.



Here's what that looks like... the rusty thing with the vacuum diaphragm. Yours is connected to hard vacuum which holds it in one position or the other all the time. Closed I think. Not good.

The part with the broken-off hose nipple is the thermal vacuum switch for the EFE valve. You need one of those. The red hose should go to the broken-off place. Pretty sure the one you need is this. https://www.autozone.com/engine-mana...34_998050_3753 Not sure if you can get it from Rockauto or somewhere.

The port on the carb that it is currently hooked to should instead go to the air cleaner. There's yet another thermostatic valve inside that, that when the car is cold, makes it draw all the incoming air through a heat stove that wraps around the exhaust manifold, and then when warm, lets it draw air in through the normal air intake.

The thing in the blue rectangle is just a fitting. The hose that goes to that, takes vacuum to the HVAC control head. That then sends vacuum to all the diaphragms in the dash that control all the HVAC doors, that route the blower output to the floor, dash, or windshield.

 

Ah yes, here it is. https://www.rockauto.com/en/moreinfo...035492&jsn=735

 

iOrdered this part, it should arrive next week.

Just need to unscrew the old one , and screw the new one ? It's air on the big tube under, not coolant liquid ?

 

There is coolant under it. But yes, just unscrew and re-screw. Use 5 - 6 wraps of Teflon tape on the threads. Tighten to maybe 8 ft-lbs.

 

Hi,
Got the part today but no luck, it's not the right size for bottom screw. the new one is smaller …


is the good one ACDELCO212632 , ACDELCO212631 , ACDELCO212618 , ACDELCO212615 ???

on mine ,it's noted on it's top cap 304 7894




I put back the old part, but the second air connector broke also, due to hot of engine and ages the plastic is burned and breack as soon as you touch it !
So i screw the old part , but now Nothing is connected on it !
To test my choke that now should be ok with all your advices, i want to drive tomorrow 15mn Morning , then the same back at evening.
Can i drive without the air tube connected in front of carb , this one ?

 

Hi,

looked all pictures and it seams it's a ACDELCO 212-615 or ACDELCO 212-618 dur to it's bottom screw size.
Where can i find the explanation of the differences between those two parts ?

Thanks

 

If you truly need the 3047894, it crosses to a 14031351 / 212-268 that appears to be discontinued. The following link goes to a USA site for reference.
I expect that in addition to thread size, there is likely a different opening temperature. I don't have the full answer, but perhaps this will help.

https://www.wholesalegmpartsonline.c.../14031351.html

The AC Delco ones you asked about are on Rock Auto--info page links follow:




https://www.rockauto.com/en/moreinfo...s53v5zUg%3D%3D

https://www.rockauto.com/en/moreinfo...s53v5zUg%3D%3D

On these type of switches, I also use "Standard Motor Parts". They often have sensors that the manufacturer discontinues.

https://ecatalog.smpcorp.com/STD/

 

Hi,

I ordered on Rockauto ACDELCO212-618
When searched the parts on internet, on amazon they also propose both, but it says 212-618 feets my Camaro Z28 1984 and 212-615 doens't feet.

Thanks for your help !

 

In case that still isn't right, here are the parts list pages that I found on line for those switches. The description provides the temperature settings and colors. The 3047894 might have been a service part as it isn't listed on the original parts list.

 

Thanks for all informations , i get the part then change it : it feets !!
BUT now i'm sure at all that in my car all is well routed .

Here is my sticker (hope it's the right for the car !! ;-) )



See from top

Who is 1 , 2 and 3 (bottom passager side) ?

And F (behind carb) is connected to …. Nothing.

Hope pictures are clear to check , confirm OR adjust !

Thanks

 

That sticker is wrong. It's for a throttle body injection motor. Assuming your car is indeed an original export qjet car, your sticker should look like mine:

 

ok, i can try to follow your sticker, my car is a Z28 1984 export, Automatic gear.
But i need help to indetify items as i don't know them :

who is 1 , 2 and 3 .... EGR , Distr , EFE ?

 

1 is your EGR valve.
2 is your vacuum advance canister
3 is your EFE (I'm assuming that's what the arrow is trying to point to?) It's at your exhaust manifold. I think Sofakingdom mentioned this earlier.