RDWRIOR Posted August 2, 2005 Report Share Posted August 2, 2005 All, Can anyone here, speaking from personal experience, recommend a reptuable source for rebuilt GM/Rochester carburetors, in particlualr the very late type involving closed loop fuel mixture control? The vehicle in need is a 1986 Oldsmobile Cutlass Ciera ('A' body) with a 2.8L V6 engine (VIN code 'X') using a two-barrel "Varajet" carburetor. The GM service part unit has been discontinued, and only some of the various GM rebuild kits are still available. Since right now I don't know what replacement parts may be needed, I think it may be best to replace the carb outright, but that means using an "aftermarket rebuild" unit. As an exercise, I check the NAPA parts Web site; they carry a replacement carb, but it cost $675.00(!) -- much more than I had expected. Thanks in advance for any help you can offer! Link to comment Share on other sites More sharing options...
tjtjwdad Posted August 2, 2005 Report Share Posted August 2, 2005 Ouch !!! Have you tried a Hemmings Motor News? You might find something in there. Carburators have gotten quite spendy but I didn't know they cost that much! Jim Link to comment Share on other sites More sharing options...
KevinW Posted August 2, 2005 Report Share Posted August 2, 2005 I don't have any experience with the VaraJet, but was wondering about the nature of the problem. I've found the E4MC QuadraJet to be extremely reliable; wear around the throttle shaft may become a problem at high mileage. ___________________________________________________ Link to comment Share on other sites More sharing options...
OynxSTS Posted August 2, 2005 Report Share Posted August 2, 2005 Road, Based on the help you have offered me I would be willing to bet that you can rebuild this yourself... QuadraJets and their two barreled VaraJet Little Brothers are easy to rebuild... I personally have rebuilt 3 QuadraJets (Olds, Chevy, Olds.. CCC too!) and 1 VaraJet (4 Cylinder Boat) All you need for a rebuild, usually, is a gasket kit... and two cans of carb cleaner... a new fuel float, a new filter (ussually in the kit) and one (or two) of those vacuum pull off thingies... Piece of cake really… Usually the problem can be traced back to a vacuum line… What makes you think you can't do it? Easin' down the highway in a new Cadillac, I had a fine fox in front, I had three more in the back ZZTOP, I'm Bad I'm Nationwide Greg Link to comment Share on other sites More sharing options...
jackc Posted August 2, 2005 Report Share Posted August 2, 2005 Beware of a rebuilt carb coming out of a mass rebuilder. The internals of the original carb are calibrated specifically for your car. Some rebuilders will use pieces that fit and work, but are not necessarily correct for your car. Some rebuilding techniques also involve molesting the original design to install mass-production pieces. I'd look first for a one-at-a-time carb rebuilder in your area. They'll be most likely to use the parts from YOUR carb. If you want to try to tackle it yourself, get this book: http://www.amazon.com/exec/obidos/ASIN/089...1817709-6459261 And before you tear into yours, get a similar one from a wrecking yard, tear it apart, and get familiar with what you'll find inside yours. If you're not up to tackling it yourself, there are alot of carby types over here who may be able to point you to a good rebuilder: http://www.chevelles.com/forums/ Hope this helps.... Link to comment Share on other sites More sharing options...
JasonA Posted August 2, 2005 Report Share Posted August 2, 2005 That Doug Roe book is an excellent book. I have it myself. Jason(2001 STS, White Diamond) "When you turn your car on...does it return the favor?" Link to comment Share on other sites More sharing options...
OynxSTS Posted August 2, 2005 Report Share Posted August 2, 2005 Dido on the book... Your local Library should have a copy... I have re-read your post and it looks like your VaraJet is a CCC model (computer command control)... Before you take it apart there are some simple steps to take to determine what issues it might have.... First... at idle... Can you hear it "ticking" it is supposed to... If it isn't you'll need a new solenoid for it Second back probe the TPS with an analog meter... look for a nice even sweep as the throttle is opened... If it doesn't you'll need a new TPS... But an ACDELCO one they are the best out there and they all cost about the same. Third these carbs, like Caddies with throw codes... any service guide will show how to make the Check Engine Light Flash and how to read the morse code. If you buy the book you will find it a little thin on Varajets... this is basically because the Varajet is a Quadrajet cut in half... If you can rebuild a Q-Jet you can do a Varajet. Good Luck! Easin' down the highway in a new Cadillac, I had a fine fox in front, I had three more in the back ZZTOP, I'm Bad I'm Nationwide Greg Link to comment Share on other sites More sharing options...
KevinW Posted August 3, 2005 Report Share Posted August 3, 2005 If you buy the book you will find it a little thin on Varajets... this is basically because the Varajet is a Quadrajet cut in half... If you can rebuild a Q-Jet you can do a Varajet. Is not the DualJet a QuadraJet "cut in half"? The VaraJet is quite a bit different. ___________________________________________________ Link to comment Share on other sites More sharing options...
OynxSTS Posted August 3, 2005 Report Share Posted August 3, 2005 IIRC The Dual Jet which was first used in '76 looked a lot like a Qjet cut east/west... Just the two tiny primaries. No air vane based monster secondaries... The VaraJet which was first used in '79 looked a lot like a Qjet cut North/South... One really puny primary and one air vane based secondary... Yes they look very different, but the basic workings... Accelerator Pumps, Air horns, Bowls, Throttle bodies, Mixture Solenoids, Floats, choke assemblies, TPS... Etc are all pretty much the same... And really rebuilding carbs is really straight forward... Take lots of digital pictures as you go, or draw lots of pictures and take your time... Easin' down the highway in a new Cadillac, I had a fine fox in front, I had three more in the back ZZTOP, I'm Bad I'm Nationwide Greg Link to comment Share on other sites More sharing options...
RDWRIOR Posted August 4, 2005 Author Report Share Posted August 4, 2005 All, Thank you for your feedback so far. The discussion of the book on Rochester carbs by Douglas Roe reminded me that I actually had this book in my "automotive library" at home. I remember buying it back in '96, thinking that it might be useful someday. (I guess that I was right!) I have pulled the book out of storage, but I have not studied it yet. The situation is that the vehicle with the problem (my father's) is located in an empty aircraft hangar in rural, small-town Wisconsin, while I, and all my tools, are located in Michigan, six hours away by car, two hours by airplane (piloted by my father). Conveniently, my father left the factory service manual in the vehicle! He's pretty sure that the problem is carb-related, so under the circumstances I thought that it might be best to just replace the carb outright instead of trying to repair or overhaul the existing carb. Given the remote location from "home base" it will be difficult enough just to perform a carb remove/replace operation, let alone a carb overhaul. Going back and forth between the work bench and the vehicle will be very impractical! The problem symptoms are: difficulty idling when cold, although idle is fine after the engine is warmed up; cruising and WOT operation are fine (after warm-up), but initial throttle "tip in" causes the engine to sag. My father says he checked the operation of the choke and the accelerator pump, and they are working fine. The vehicle sat unused for 12 months, so fuel contamination came to my mind as a cause, but I am not sure that it entirely explains the symptoms described above. In spite of its age, the vehicle has only about 25,000 miles on it, and is otherwise in excellent condition. So, I doubt "wear out" issues explain the problem, although I suppose rubber hose and/or gasket aging could. In any case, I have absolutely no hands-on experience with carburetors, whatsoever! Given all that, I contemplated going with a replacement carb. But, when I found that the GM service part carb had been discontinued, and it appeared that there was only partial availability of GM rebuild parts for the carb, I knew that I would have to rely on the aftermarket, which is why I started this thread. Right now I'm still thinking about what to do. I think that I will try to find a copy of the GM service manual in our "library" here at work, but it is a "read/copy on premises only" arrangement there -- no borrowing. If anyone has any ideas, please feel free to share them. Link to comment Share on other sites More sharing options...
OynxSTS Posted August 4, 2005 Report Share Posted August 4, 2005 First I would check all of the vacuum lines... There will be about 24' of them in total ranging from 1/4"s to 3/8"s Bet one or more is rotted and is leaking A vacuum leak will cause a crummy idle and bog at all engine speeds but this will be most noticeable cold… pay extra attention to line to the EGR valve. A leaky EGR, its supposed to be closed at idle, will also cause idle issues. Shoot, on a car of this age I would replace all of the vacuum lines… It can’t hurt. This is the easiest and cheapest thing to do first. And the only tool you need is a pair of scissors. Easin' down the highway in a new Cadillac, I had a fine fox in front, I had three more in the back ZZTOP, I'm Bad I'm Nationwide Greg Link to comment Share on other sites More sharing options...
KevinW Posted August 4, 2005 Report Share Posted August 4, 2005 The problem symptoms are: difficulty idling when cold, although idle is fine after the engine is warmed up; cruising and WOT operation are fine (after warm-up), but initial throttle "tip in" causes the engine to sag. My father says he checked the operation of the choke and the accelerator pump, and they are working fine. The vehicle sat unused for 12 months, so fuel contamination came to my mind as a cause, but I am not sure that it entirely explains the symptoms described above. In spite of its age, the vehicle has only about 25,000 miles on it, and is otherwise in excellent condition. So, I doubt "wear out" issues explain the problem, although I suppose rubber hose and/or gasket aging could. Did this car run perfectly prior to the 12 month storage? I would expect the fuel to be OK for the most part, possibly some mild driveability concerns prior to manifold heat taking effect because of loss of volatility. I assume that checking operation of the choke involved assessing the tension of the choke coil while cold, and observing the degree of opening following a cold start (primary vacuum break action). This setting determines the fuel mixture after the initial pull-over enrichment (while cranking) and accelerator pump shot (from setting the choke) has been consumed. Considering the low mileage, I would expect that all the adjustments are original, and worked satisfactorily prior to the storage period. I would focus attention on the other choke components. Depressing the accelerator prior to starting allows some parts to move into position (force from the choke coil) to hold throttle at a position above the warm idle setting. As the choke coil tension relaxes (as the engine warms up), the idle speed is allowed to drop in a step-wise fashion. Verify that the various choke components move freely, and are able to move on their "own" (from the effects of gravity, where applicable). The warm tip-in sag, depending on the magnitude, might indeed be vacuum leak related. Most damage to "soft" parts is a result of cumulative exposure to heat, which I would not expect in such a low mileage example, however, there's always the possibility of curious rodents! ___________________________________________________ Link to comment Share on other sites More sharing options...
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