Source for new Cadillac Carburertors?

[GBrown #8092]

Several months back in a message chain, someone posted the name of a vendor who was selling new carburetors appropriate for our cars. As many know my '72 suffered a major meltdown on the way to the 2017 GN. After having everything triple checked everything that was replaced in the ignition system, despite a new coil and timing gear and other parts, it still does not idle to my satisfaction.   

Two experts have suggested that the carb on the car, which has been identified as an off the shelf rebuild with misc parts (by the person who rebuilt it just before the trip) is probably the problem.  That said, rebuilding what I have is not really a good option.

I had the name bookmarked, but the computer took a dump and lost all my saved bookmarks.  I thought it was "Universal", but as you might suspect, I can't google search that.  Does anyone remember/know what the name of that carb seller was?

Appreciate it. Would like to get this resolved, and gets some miles on it before the 18 hour trip to Texas.


Glenn

["Cadillac Kid" Greg Surfas 15364]

Glenn,
If the carburetor performs satisfactorily for every other condition other than idle, AND the idle screws are not damaged then you should be able to get it to idle correctly.  If you are still going through the Thermal Vacuum valve and the TCS circuits, then for anything other than a brand new motor, i9dle is VERY difficult to smooth out.  What I did on mine was to circumbent the Emissions vacuum circuits and took the vacuum advance can source directly off Intake manifold vacuum.  Be sure the vacuum can is correct as replacement by the wrong one will not result in the best performance.
I set my initial advance at about 10 degrees(wth the vqcuum disconnected) and followed the shop manual procedure for adjusting the carburetor idle,
If you are still wanting to replace the carb I would suggest you contact Jet Performance.  They do a great job.
Greg Surfas

[TJ Hopland]

Is your current carb not a Cadillac carb?   It takes a lot of abuse to make it so a good carb shop can't make one right.

Anything other than a Cadillac Quadrajet carb takes some modifications of both the carb and car to make em work.  Its not necessarily major modifications but can turn out to be a real hassle.    If yours is beyond repair I would try to find a correct used one and get it rebuilt by a good shop.   

[GBrown #8092]

Thanx Greg, We'll try that.
TJ the rebuilder says is a frankenstein, apparently an off the shelf rebuild built from an assortment of Q jet parts, but should work. One of my two mechanics suggest that the base plate is wrong and the the idle air openings may be too small, but that is from a visual inspection. The shop that rebuilt it and  teh installer are baffled.

We'll try Greg's suggestion, once it finally warms up and stops snowing up here, and see if that helps.

Glenn

["Cadillac Kid" Greg Surfas 15364]

What's snow?
Greg Surfas

[TJ Hopland]

I don't know the innards of Qjets that well so its certainly possible that there are differences in the base plate.  Base plate would also be a part that often gets replaced due to warping or throttle shaft bore wear.  Good shops just bush the shaft bores but I could imagine a bulk rebuild shop thinking it was better (cheaper for them) to have a supply of one size doesn't really fit all universal replacements.

Have you got the idle mixture screws all the way in or all the way out?   Do they seem to have a significant effect on the idle quality or not really? 

This has a stock 72 intake on it so no EGR?

Have you tried isolating for testing vacuum devices like level ride, transmission, and brake booster to make sure one of those isn't leaking more than they should?

AC compressor still in place?   There is one bolt for the compressor that goes into an intake runner.  No bolt= big leak.   

[Scot Minesinger]

vacuum leaks often cause a rough idle, so I would look for those.  All vacuum hoses that are original should be replaced even though they may look ok.  Even if they are in question, since they are so inexpensive and easy - just replace them.  The vacuum lines most often missed: PCV to carb, cruise thru firewall to brake switch, and feeder to e-brake release switch on steering column.  After vacuum lines are replaced, the car will need to be re-timed and probably idle speed adjusted. 

Check to be sure that the distributor was out back correctly (not a tooth off), this can be done by checking the timing mark with timing light - if you see it on driven pulley with light then it is in correctly.

Agree with idle adjustment screws, that makes a world of difference for a nice smooth idle.

If your carb installed now is a "Frankenstein" replace it with a correct original one.  One source that has worked for me is Cadillac King in CA, google them, and order one by phone.  It will arrive ready to bolt on, but you will need to adjust idle and idle mixture screws.  I was lucky enough to find an NOS 1970 carb on e-bay and that was an awesome find - it is installed on my SDV and it runs super smooth.

["Cadillac Kid" Greg Surfas 15364]

Glenn,
If worst comes to worst I've got a '73 carb that I re-jetted (and re rodded) for my 72.
Greg Surfas

[dochawk]

This is months later, so I hope you've solved it, but just in case, it might have been one of my posts.

When I needed one, I actually had a choice of three Delco rebuilt 1972 cadillac carburetors on eBay.  I don't see any today.

I think I paid a bit over $200; it came in the deco box and still shrink-wrapped . . .

hawk

[gkhashem]

I am confused by this thread. There seems to be plenty of internet sites selling rebuilt carbs and the correct ones for your car.

Why not get a one of these and pay the core deposit. Yes expensive but would that solve the problem?

[Steve Passmore]

Strange that the OP has never returned??

[GBrown #8092]

Alive and well. I'm guessing"OP" = original poster.

Fought with it myself for a bit without success. My traveling mechanic was stumped as everything was set correctly, there appeared to be no vacuum leaks, and re-builder insisted the carb was fine.  I had my doubts, as did several others, so was going to just replace the carb. One source also did suggest that the wrong base plate might be the issue, but wasn't willing to take it on. I had rechecked the vacuum hoses and they seemed okay. We were not able to find and vacuum or intake leaks.
BTW: the vendor i was looking for had new carbs on sale for under $200 (never did find him again).

I decided to hold off on a new carb until i was sure that it  was actually the problem.
I have another shop I do business with who has been very, very good at ferreting out the cause of problems when others have failed, plus I didn't want to buy another carb if I didn't need it, so took it to him. He was very busy, so would only take it in for diagnosis only at that time.   He said at minimum, I need a new choke pull off, he suspects there is an issue in the idle circuit as  it runs fine on the highway, and he had several other ideas he wanted to explore, but I was running out of time to get it ready to go to the GN in the few weeks left before the GN,  so I dropped dealing with it for awhile.  As I didn't want to duplicate last years break down experience on the way to Texas, decided to deal with it later. I'll be getting back to it shortly.

Thanx for the suggestions, they were not in vain

Glenn

[James Landi]

Not wanting to add to your confusion and anxiety, but I have a Holly that had a partially clogged idle passage that gave me no end of issues... the engine would idle fine for 15 seconds, begin to blog down, and unless I could get on the accelerator and the traffic pump to bring the engine rpm up to 1500 rpm, the engine would stall.   The problem-- caked in ethanol fuel separation gunk stuck in the air/ fuel idle passage... a shot of compressed air through the idle air adjustment jet screws solved the problem..  (and by the way, I shot a good deal of carburetor cleaner (aka GUM OUT) into those holes... it was compressed air that moved the unseen gunk out of the tiny passages...   Happy day to you,   James