What type of carburetor can I use to replace my old one?
Cadillac
 

Cadillac Forums | Help Us Help You | Advertise | Cadillac Parts | Cadillac News | Cadillac Classifieds / (Old System)

Cadillac Technical Archive | Cadillac Dealers | Cadillac Reviews | Cadillac Dealer Reviews | Cadillac Vendors

CadillacForums.com is the premier Cadillac Forum on the internet. Registered Users do not see the above ads.
+ Reply to Thread
Page 1 of 3 1 2 3 LastLast
Results 1 to 15 of 35
500, 472, 425, 368 Discussion, What type of carburetor can I use to replace my old one? in Cadillac Engine Technical Discussion; I have a 79 coupe deville with a 7.0L engine, and my car needs a new carburetor, or my old ...
  1. #1
    tha_customizer is offline Cadillac Owners Member
    Join Date
    May 2004
    Posts
    68

    What type of carburetor can I use to replace my old one?

    I have a 79 coupe deville with a 7.0L engine, and my car needs a new carburetor, or my old one can be rebuilt. Is rebuilding an easy task if I pay attention? Also, for a replacement, I was looking to buy either a Holley or Edelbrock carburetor, but I'm not sure if they are compatible with my engine, since I was told that mine is controlled by a computer or something like that... Please inform me of what type of carburetors I can use as replacements, or rebuilding info, as I was looking at purchasing a 1400 or 1406 Edelbrock carburetor... Any info would be helpful!

  2. Remove Advertisements
    CadillacForums.com
    Advertisements
     

  3. #2
    davesdeville's Avatar
    davesdeville is offline Banned
    Automobile(s): 1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
    Join Date
    Aug 2003
    Location
    Albuquerque, NM
    Age
    26
    Posts
    7,971

    Re: What type of carburetor can I use to replace my old one?

    Rebuilding a Quadrajet is not an easy task unless you're experianced or God himself. Yours is not controlled by the computer in any way, although later Quadrajets on Olds 307 cars were. I'd find a local carb shop and have them rebuild it, or google Quadrajet rebuild..

    Edit: Err, it's not controlled by the computer because there is no computer in a carbureted 79.

  4. #3
    Johnny Bravo is offline Cadillac Owners Fanatic
    Join Date
    May 2006
    Location
    New Jersey
    Posts
    131

    Re: What type of carburetor can I use to replace my old one?

    Make your life easy, get the stock Quadrajet rebuilt and be done with.
    Don't open up a can of worms fooling around with an aftermarket carb. By the way, a 1979 engine should not have a computer controlled carb.

    See links for some good rebuilders:

    eBay Store - Remancarbs: GM Carburetors, GM TBI Fuel Injectors, GM Vortex unit 6 Cylinder

    eBay Motors: Chevy 350 Heavy Duty Carburetor Rochester 4 bbl Carb (item 140034254102 end time Oct-01-06 14:08:19 PDT)

  5. #4
    N0DIH's Avatar
    N0DIH is offline Cadillac Owners Master
    Automobile(s): 94 Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Rockford, IL
    Age
    47
    Posts
    7,489

    Re: What type of carburetor can I use to replace my old one?

    Honestly, if $$ is the big issue, and you want new, go with a #1411 AFB. Being it is a 425 and really likely will never need a full 750 cfm, you might go with the #1406, it is only 600 cfm, but being you never see over 5000 rpm, might be a better realistic choice. I have a #1407 that I put on the electric choke and honestly a lot of the time wish I had the 600 cfm, as 750 was overkill. But I had bought it when I had the 455 in the car. Even then I thought the 750 was bigger than it needed to be most of the time (I was working on mpg... 3.08's THM350 and 3000 rpm cruise and I got 15.5-16 mpg...)
    Look at this:
    http://www.edelbrock.com/automotive_..._app_chart.pdf

    The carbs that are "calibrated for economy" are typically set up with electric choke and some revised boosters that the non economy carbs don't have, it is n't as simple as just a rejet kit and you have the other (I know, I have them all...)

    You won't regret the AFB, the tunability and simple functionality and cost are second to none. The Holley's won't get the mpg at all, the Q-Jets are just plain old now, and new ones are $$$$, AFB's that Edelbrock manufacture and decent quality (I have heard of some crappy ones too). I have 2, 1 new from Edelbrock (Summit) and 1 from eBay that I got for $70.

    I am fond of Q-Jets, and can make them run good, but you can't get a BOP type new at all, (all new ones have goofy Chevy style fuel inlets) and they can be $$ to fix to make them like new. $$ best spent into a new carb.

    There is a guy I spoke with in Rockford, IL who has a business restoring and rebuilding Q-Jets. He really does know his stuff. I can see if I can find who him if you want to see about doing that.

    OR, you can do what I want to do on my T/A, get a 747 PCM and TBI and make it a TBI 400 Pontiac... That would be quite easy and relatively low cost today. Probably spend no more than $400 doing it.

    Try this:
    Get a 368 EFI distrib, intake/throttle body, TPI PCM and wiring harness and just make it port EFI like the 6.0L were. But with a PCM that can be tuned well.

  6. #5
    kevin666's Avatar
    kevin666 is offline Cadillac Owners Member
    Join Date
    May 2006
    Posts
    49

    Re: What type of carburetor can I use to replace my old one?

    I recently had my Q-jet rebuilt and I couldn't be happier. They are the best all-around carb for mileage and reliability. Freshly built ones perform very well, also. Any Holley I ever ran was a gas guzzler, although I have never tried their Q-jet replacement, as it is expensive as hell. I would get the Rochester rebuilt if the throttle shft is not worn out...

  7. #6
    Wheelman322's Avatar
    Wheelman322 is offline Cadillac Owners Enthusiast
    Automobile(s): 1980 FWB Coupe D'el, 1995 FWB & 6 Other Non-Cadillacs.
    Join Date
    Nov 2003
    Location
    New Jersey
    Posts
    724

    Re: What type of carburetor can I use to replace my old one?

    I had my Q-Jet rebuilt by a very reputable carb. guy, and it sucks. I am looking into doing the F.I setup that NODIH recommended. If I don't go that route, I will go with an Edelbrock model. Anyone that knows anything about carbs will tell you that Holleys are not a good choice for a Cadillac. From what I understand Edelbrock bought the old Rochester molds and makes a pretty good setup for a 425.

  8. #7
    Johnny Bravo is offline Cadillac Owners Fanatic
    Join Date
    May 2006
    Location
    New Jersey
    Posts
    131

    Re: What type of carburetor can I use to replace my old one?

    Quote Originally Posted by N0DIH View Post
    You won't regret the AFB, the tunability and simple functionality and cost are second to none. The Holley's won't get the mpg at all, the Q-Jets are just plain old now, and new ones are $$$$, I am fond of Q-Jets, and can make them run good, but you can't get a BOP type new at all, well.
    With all due respect, the AFB carb is a pretty old design as well. The current AFB is based on the old Carter AFB that is as old, if not older, than the Q-jet. Argueably, the Q-jet may be considered the height of carburator development before the advent of modern fuel injection. GM used them on vehicles from the mid 1960's to 1990.
    Ironically, Chrysler which was a big with AFB carbs in the 60's used Q-jets on some vehicles in later years.

    You just can beat the Q-jet's combination of small primaries for excellent fuel economy/throttle response and the huge secondaries for WOT blasts.

    Moreover, a rebuilt unit, if done well, is probably better than new in most cases.

  9. #8
    Wheelman322's Avatar
    Wheelman322 is offline Cadillac Owners Enthusiast
    Automobile(s): 1980 FWB Coupe D'el, 1995 FWB & 6 Other Non-Cadillacs.
    Join Date
    Nov 2003
    Location
    New Jersey
    Posts
    724

    Re: What type of carburetor can I use to replace my old one?

    Try this:
    Get a 368 EFI distrib, intake/throttle body, TPI PCM and wiring harness and just make it port EFI like the 6.0L were. But with a PCM that can be tuned well.[/QUOTE]

    If I was to duplicate this setup, would I need all of the sensors to go with it (I.E: MAF/TPS/etc... etc...)? What about the fuel delivery...Could I leave the mechanical pump, or would I need to upgrade to electric.

  10. #9
    Wheelman322's Avatar
    Wheelman322 is offline Cadillac Owners Enthusiast
    Automobile(s): 1980 FWB Coupe D'el, 1995 FWB & 6 Other Non-Cadillacs.
    Join Date
    Nov 2003
    Location
    New Jersey
    Posts
    724

    Re: What type of carburetor can I use to replace my old one?

    Try this:
    Get a 368 EFI distrib, intake/throttle body, TPI PCM and wiring harness and just make it port EFI like the 6.0L were. But with a PCM that can be tuned well.[/quote]

    If I was to duplicate this setup, would I need all of the sensors to go with it (I.E: MAF/TPS/etc... etc...)? What about the fuel delivery...Could I leave the mechanical pump, or would I need to upgrade to electric.

  11. #10
    N0DIH's Avatar
    N0DIH is offline Cadillac Owners Master
    Automobile(s): 94 Fleetwood Brougham
    Join Date
    Aug 2004
    Location
    Rockford, IL
    Age
    47
    Posts
    7,489

    Re: What type of carburetor can I use to replace my old one?

    Mandatory to get an electric, you need 43.5 psi. So a TPI pump or even a 368 in tank pump is required. Make sure the fuel lines are up to snuff too. Ideal would be to adapt a LS1 returnless system to it.

    Find a boneyard car that has it all and pull it. Painless Wiring can probably help too. Remember the Cad V8 was EFI from 75 or 76 as an option up through 1980 or so, then all were. So a Cad intake manifold and sensors likely aren't too far off, just might need a TPI sensor in place of the Cad one if the range is different.

  12. #11
    davesdeville's Avatar
    davesdeville is offline Banned
    Automobile(s): 1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
    Join Date
    Aug 2003
    Location
    Albuquerque, NM
    Age
    26
    Posts
    7,971

    Re: What type of carburetor can I use to replace my old one?

    Quote Originally Posted by Johnny Bravo View Post
    You just can beat the Q-jet's combination of small primaries for excellent fuel economy/throttle response and the huge secondaries for WOT blasts.

    Moreover, a rebuilt unit, if done well, is probably better than new in most cases.
    Most definately. (assuming you mean "you just can't beat.")

  13. #12
    Wheelman322's Avatar
    Wheelman322 is offline Cadillac Owners Enthusiast
    Automobile(s): 1980 FWB Coupe D'el, 1995 FWB & 6 Other Non-Cadillacs.
    Join Date
    Nov 2003
    Location
    New Jersey
    Posts
    724

    Re: What type of carburetor can I use to replace my old one?

    My Cad was originally a F.I car and was converted to a carb. setup by the previous owner. Can I work with my existing wiring harness?

  14. #13
    Wheelman322's Avatar
    Wheelman322 is offline Cadillac Owners Enthusiast
    Automobile(s): 1980 FWB Coupe D'el, 1995 FWB & 6 Other Non-Cadillacs.
    Join Date
    Nov 2003
    Location
    New Jersey
    Posts
    724

    Re: What type of carburetor can I use to replace my old one?

    Quote Originally Posted by N0DIH View Post
    Mandatory to get an electric, you need 43.5 psi. So a TPI pump or even a 368 in tank pump is required. Make sure the fuel lines are up to snuff too. Ideal would be to adapt a LS1 returnless system to it.

    Find a boneyard car that has it all and pull it. Painless Wiring can probably help too. Remember the Cad V8 was EFI from 75 or 76 as an option up through 1980 or so, then all were. So a Cad intake manifold and sensors likely aren't too far off, just might need a TPI sensor in place of the Cad one if the range is different.
    My Cad was originally a F.I car and was converted to a carb. setup by the previous owner. Can I work with my existing wiring harness?

  15. #14
    Benzilla's Avatar
    Benzilla is offline Cadillac Owners Connoisseur
    Automobile(s): '79 Phaeton, '90 Brougham, '79 CDV
    Join Date
    Oct 2005
    Location
    Chattanooga, TN
    Posts
    4,287

    Re: What type of carburetor can I use to replace my old one?

    Quote Originally Posted by Wheelman322 View Post
    I had my Q-Jet rebuilt by a very reputable carb. guy, and it sucks. I am looking into doing the F.I setup that NODIH recommended. If I don't go that route, I will go with an Edelbrock model. Anyone that knows anything about carbs will tell you that Holleys are not a good choice for a Cadillac. From what I understand Edelbrock bought the old Rochester molds and makes a pretty good setup for a 425.
    Wait, how does it "suck"? I'm looking into having mine rebuilt, and i'd like to know if you have a real reason why I shouldn't.

  16. #15
    Wheelman322's Avatar
    Wheelman322 is offline Cadillac Owners Enthusiast
    Automobile(s): 1980 FWB Coupe D'el, 1995 FWB & 6 Other Non-Cadillacs.
    Join Date
    Nov 2003
    Location
    New Jersey
    Posts
    724

    Re: What type of carburetor can I use to replace my old one?

    Quote Originally Posted by Benzilla View Post
    Wait, how does it "suck"? I'm looking into having mine rebuilt, and i'd like to know if you have a real reason why I shouldn't.
    When it's cold, it stalls several times, It's shaky at idle, It sucks fuel like crazy, it stumbles at takeoff and If you floor it it will stall.

Quick Reply Quick Reply

Register Now

Please enter the name by which you would like to log-in and be known on this site.
If you do not want to register, fill this field only and the name will be used as user name for your post.

Please enter a password for your user account. Note that passwords are case-sensitive.

Please enter a valid email address for yourself.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Bookmarks

Cadillac Posting Rules

  • You may post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
Read about Lincoln | Buick | Kia Forte Forum
Need products for your Cadillac? Check out your options at the links below:

custom floor mats | Cadillac Chrome and Black Chrome Wheels | window tinting