Hi guys, i have a 70 coupe deville. I picked up the car about a month ago. I drve it home, about a 2 hr drive, and the whole way back if i put the pedal to the floor, it would bog out. i could get it up to 75 no problem, but if i wanted to open it up, it just bogged out

so i figured id rplace the carb. after reading alot of threads on this forum i had read that keeping the quadrajet was the best option. So i managed to find one on ebay. The acution said it was for a 70. But when i got it, i ran the numbers and said it was off a 72. Now they were basically identical except for a few things.

1, the fuel bung is a different size. Not a big deal, i just replaced the fitting, and used a small length of rubber hose.

2, On the passenger side front of the carburetor, On my original 70 carb it had a small pin with a spring sticking out the top. The new 72 unit does not.

Old:
http://img.photobucket.com/albums/v179/sjm98126/IMG_0565.jpg

New:
http://img.photobucket.com/albums/v179/sjm98126/IMG_0574.jpg


Now i put the carb on the car. And it starts up, idles VERY rough, and backfires.. I did not have any of the vacuum hoses hooke up. I am not sure where they are supposed to go. I found a diagram on another thread on here, but there were a few extra parts in the diagram, that i do not have on my car.


Now, i really dont have any experiece with carbs. so this is kinda new to me.

A guy i work with told me that the heat sensitive choke spring should allow the primaries to stay wide open at temp. weather its at idle or not.

What im confused on, is i read something on another site. believe it was a corvette site, They siad that the secondaries begin opening at 50% or so of the primaries being open? So if the chokespring keeps the primaries Wide open, how does that work?

The car right now barely runs, it idles real rough, and has NO power. it rev's VERY slow, and probly doesnt get past 2500 or so. Giving it full throttle makes it backfire and stall. i managed to get the car to creep up my driveway. But i had it towed to my shop, which has a SMALL incline going into the bay door, and it wouldnt budge.

Im trying to figure out where i should start, in setting up this carb to work on my car. If in fact it will work at all.

the old carb number was 7040230 And the new carb number is 7042234.

The choke pulloff on the new carb is hooked up a little different than it was on the old one. I honestly dont remember where it went before, i was stupid, forgot to lable things, and just pulled it all off.

But heres a pic of the old choke pulloff, and how the new one is routed.


Notice the direction that the vacuum port is facing.
http://img.photobucket.com/albums/v179/sjm98126/IMG_0565.jpg

New:
http://img.photobucket.com/albums/v179/sjm98126/IMG_0571.jpg



Now Heres some pics of the vacuum hoses and what not. If anyone can give me some insight as to how i need to hook everything back up, it would be greatly appreciated.


Front of the carb:
http://img.photobucket.com/albums/v179/sjm98126/IMG_0577.jpg

back of the carb:

http://img.photobucket.com/albums/v179/sjm98126/IMG_0578.jpg

http://img.photobucket.com/albums/v179/sjm98126/IMG_0576.jpg


And this hose
http://img.photobucket.com/albums/v179/sjm98126/IMG_0579.jpg

which runs into this:
http://img.photobucket.com/albums/v179/sjm98126/IMG_0580.jpg

And then the vacum advance on the distributor.

Id appreciate any help anyone can give me.

Your ebay quadrajet may be suspect. a general rule of thumb is that most comercial rebuilders do damage to good cores and make them unusable. The number you provided indicates it is a 72 Cadillac. The last digit being a 4, an even number means automatic trans. The fourth digit in a 2 means a 1972.
Quadrajets are very sensitive to vacuum and having the vacuum hoses hooked up properly is mandatory as well as the carb gasket itself.
I would go back to your original carb and look at adjusting the spring tension on the air door. If it opens too quickly you will experience a bog. The best way to do this would do a google search on Quadrajet and look for troubleshooting hints and specifically setting the air door spring.
Do not overlook ignition problems. Make sure your plugs look good and are the proper heat range and gap. Make sure your dist cap is good and that the mechanical advance and vacuum advance are working. Common to find the diaphragm on the advance canister leaking.
It sounds like you have much to learn. Do alot of reading and find a good old mechanic to help you out. Hang in there with the quadrajet, they are complicated but excellent carbs.

If you are trying to run it with all those vacuum ports open then it probably won't run. If you can't figure out where the lines go, at least plug the vacuum ports on the carb. Is the choke staying closed after it starts? With all those nice pictures you took, I hope you have a before shot of the vacuum hoses. I'm betting that new ebay carb will work fine once it's hooked up right and adjusted. Good luck.

The choke stays wide open after a minute or 2 of running. when it cools back down it closes up again. it doesnt take very long tho. a minute or two, and it opens all the way up. As for before pictures.. I dont have any. otherwise i woudnt be asking for help lol. I had a beer or two too many before i started working on it, and got in one of those moods where i said "screw it, i'll figure it out later" Either way, i dont think the hoses were connected properly anyway when i got the car, i dont remember the vacum advance on the distributor being hooked up at all, and there was a hose or two that were plugged with a screw in the end. The car has been mesed with, someone tried a lame attempt at a "restoration" which included riveting sheet metal over rot holes in the trunk, and wadding it with undercoating.

When i got the car the exhaust manifolds were leaking badly.. there was no gaskets in them, And the original manifold to head bolts were missing, and replaced with ones that were too long. And they used some Nuts to space out the bolt so it actually tightend the manifold. Thats the main reason i pulled the engine apart. i had to fix the exhaust manifold leaks, And of course, i snapped off every bolt in the head. so i had to pull the head extract the bolts out of the heads.. And i had 2 that needed to be drilled and tapped. The drivers side exhaust port closest to the firewall had no bolts at all in it.. And when i pulled the head off to take care of the rest of the studs i noticed someone apparantly triedto melt the bolt out of the head with a torch. Because there was a nice big crater in there where the bolt should screw into. So my guess is, if they hacked stuff like that up.. who knows what else they did with the rest of the engine. Thats why i want a definitive diagram of how everything should be setup. Im in no rush right now. I got the car out of my driveway, and up to my shop, where im taking care of all the bodywork, And im going to pull the motor out to freshen it up. gaksets, bearings, freeze plugs, new cam and lifters, all that good stuff. So it will be a couple weeks before i get to the point where i am putting the motor back in and getting ready to fire it.

Hey first time poster here.
I have a -70 Coupe DeVille which had a Holley carb on it when I bought it. I bought a Rochester Qjet from Ebay and have been looking like crazy for a vacuumdiagram for my carb. This is what I´ve come up with so far:

The big vacuumport on the front of the carb (under the fuelline) should be connected to the passengerside valvecover.

The small vacuumport on the front should be connected to the small hose coming from the distributor.

The big port on the back of the carb connects to the line coming from the brakeservo.

The small one on the back (the lower of the two small ones) should be connected to the tranny.

The last one I still don't know where to put. The thing is if you hook them up and it runs like crap, just move the hoses around a little until it runs better. You can't really destroy anything if you connect it wrong. I've ordered a shop manual on cd from Ebay, when I get it I'll let you know if I find something definitive.

/Inferno