I have a 1963 Riviera and have had nothing but problems with the carb. The original Q Jet was in pretty bad shape so I replaced it with an Edelbrock (AFB style). The problem is I have a real bad off idle stumble, and I don't know what to do about it. It is a pain to drive it. Help!
It has the factory intake, I have the original 4 Jet (actually it is not a Quadrajet), but I have this aftermarket Edelbrock (AFB copy) that is acting up.
Do you have the budget to send your original carb to a specialist like Carmen Faso? Quality rebuilds usually run $250-300, depending on what has to be done. You can't go wrong with one of the well-known Buick carb guru's.
Yes, but, it is antiquated, and difficult to tune....that's why I wanted something more modern. I am a little reluctant to send my original carb off to someone I don't know and "hope" I get the same thing back but working properly. I was hopeful that someone on this board had some specific experience and pointers on dialing the Edelbrock in...since it seems to be the only aftermarket "modern" carb available.
Off idle stumble could be as simple as the accelerator pump acting up. This is the rod on the right front (as seen from the drivers seat) of the carb. If the carb idles ok and goes down the road ok, I would check the accel. pump first. make sure the external linkage is ok, if not-try a new accel pump. they are only a few ($10?) bucks and easy to install. If not, you may want to start checking other stuff like vacuum lines/leaks, ignition timing/advance etc... sometimes what seems to be carb related is far from it.
Ok,.... Not sure if this matters, but I had an Edelbrock on my old 71 LeSabre, and it had a pretty nasty off-idle stumble/hesitation. I swapped back on an original qjet, and it was like a new car. I don't have any personal experience tuning the Edelbrocks. I hope you can work out that stumble. I finally gave up on mine. Are you sure it's the carb that is the problem? Ignition timing can play a huge part in "stumbles"....have you timed the engine recently?
It will be better if you send it to Carmen. I have a Q-jet and a Carter AFB rebuilt by him, and both look and perform better then new. He will rebuild it for the application and modifications you have. Just be sure to ask when he expects it to be done as he collects a few to do all at the same time. The # is 716-693-4090, and he is near Buffalo, NY. Cheryl
Edelbrocks come with step up springs...the ones they use from the factory are very light for engines with big cams...you need them to be stiffer...this should do the trick but I was never able to totally work the stumble out of mine on my Skylark, so I switched back to the original Carter...if you want to tune this Edelbrock, look in the owner's manual if you have it...they have a pretty good tuning section.
Thanks for the pointer. I will dig up the manual....but I think I might have to go back to one of the old carbs! Either the 4 jet or the CArter.
I wish I knew if the edelbrock plunger would fit an old carter.......and if they are made of leather or neoprene. Anyhow, the leather ones in the older carbs really SUCK! It took me a lot of screwing around to fix mine and I think it could still be a little bit better...........ou:
I have an old Carter AFB out in the garage I will dig up...it is from the junk yard 401 I used to build to replace the original 401 that my father blew up (cracked the block and bent the rods!) back in 1981. I will check out the plunger seal...
That would be awesome......Carter carbs are great by design, but IMHO that plunger is very unreliable. A modern neoprene replacement would solve a lot of problems IMHO. :Brow:
The old trick is to peel the leather plunger back over its self one time and then soak it in trans fluid. There is some adjustments to the plunger too. some had more than one hole on the top end of the plunger shaft. plus the adjustments to the actuating arm. I put a 600 cfm Holley on my 64 riv. It runs sooo much better. I made a adapter from 1/4 '' hot rolled steel and changed the air cleaner to a 67 riv air cleaner. I took all the vac door junk off the air cleaner and welded the holes up. I liked the larger snorkel intake.
Chevy friends have been saying I should adapt a Holley as well. Was it a matter of making a plate with holes that match the intake hole pattern and holes that match the Holley pattern and brazing nuts to the holes? Did you mill a large center square hole? I understand that Holleys are much easier to tune....
Scott, The best set up would be a spreadbore [1966] manifold with a 800 cfm holley. Now, you could do like I did and cheat. he he. I took my stock single 4 manifold and cut the dividers out between the front and rear barrels, leaving the cinter divider in. this keeps the torque. then I made a adapter that matched the manifold. i made it out of 1/4'' hot rolled steel. I used the manifold/carb gasket for the pattern of the bolt holes. [1966 buick afb gasket] You drill the bolt holes that will hold the adapter to the manifold and champher them to use counter sunk screws that will fit flush with the top surface. next take the holley gasket , put it on the adapter so it matches the manifold bores[ which are now 2 ovals that flow much better btw] and lay out the bolt hole centers for the studs that will hold the carb on. drill and tap the holes to 1/4-20 threads. you wont need nuts. Bolt the carb on and check the throttle butterflies for interference. then it is just a matter of hooking up the carb linkage. I used a plasma cutter to cut out the throttle bore openings and the outside shape of the adapter plate. then I finish ground it with a die grinder and a carbide burr. next i finished the edges with a dremel tool and sanding drum. Be really carefull laying out the centers of the bolt holes and stud holes. they have to be pretty well right on the money or the adapter plate will not work. also make sure that the heat riser channell is covered right, the adapter plate will be your carb heat shield. i used my stock intake manifold/ cut the dividers out / i already had the piece of 1/4 plate/ I bought the carb in a junk yd for $10 and rebuilt it , kit $25.00- 1967 air cleaner-$25.00 I now have a 600 cfm holley, rebuilt, cold air pkg. for about $70.00. The car runs much stronger .
I wouldn't put a Holley on my lawn mower......personal preference.....but to each is own I guess......IMHO, for the best overall performance, the way to go to get the '66 spreadbore manifold and go with a quadrajet done up right.
Some interesting ideas....I need an excuse to buy that plasma torch! Re the spreadbore manifold...it sounds like the '66 manifold is setup different than my '63...is this true?
