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Discussion Starter #1
My Caddy will be off the road until at least the spring time now, and so it is a good time to start doing a little more in depth work than just fluid changes I have been able to do since I bought it at the end of the Summer. I was thinking maybe I should rebuild the carb on my 1970 SDV w/472. The car runs pretty dang good right now as it is but I wouldn't be surprised if the carb has never been rebuilt in the cars 90,000 mile lifespan. What are the symptoms of a tired carb? I have noticed that when I floor it even when it is warm it almost stalls for a split second, then roars to life, although I suppose it could be the accelerator pump as well? While I have the carb off, would it be a good idea to take off the intake manifold and heads as well and just to a good cleaning of the engine and replacing of the gaskets? How hard is it for someone who has no experience in rebuilding carbs to do so? I do have the factory service manual for my car and a lot of patience and time. How do I get the carb number for the rebuild kit? Is it the same for every carb of that year or is it different for every carb made?
 

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Go for it. If it's off the road for the winter, you'll have plenty of time to work on it without being under pressure to get it done now. Actually, the rochester 4 is not difficult to rebuild. For the first timer, I suggest a little reading but most important, take your time and pay attention to detail. You will really learn a lot.

I think it's time anyway. More than likely the needle valve is worn and the float has soaked up some gas. The accelerator pump is probably worn like you say and you'll probably find some junk sitting on the bottom of the bowl.

Good luck with this project.
 

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1976 Eldorado project
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Buy Doug Roe's book on Rochester Carbs, it includes a really in depth part about the Q-Jet, rebuilding it, etc etc. Probably the best Q-jet book out there.
 

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Discussion Starter #4
Would it be a good idea to remove the heads and glean all the gunk outta the block/heads that I can find and replace all the gaskets I find? Or if it isnt leaking or anything is it good to just leave well enough alone and stop at the carb?
 

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1976 Eldorado project
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I don't think you should remove the heads, only because I don't see how it could benifit you in any way. I would remove the valve covers to check the rockers. There may be some sludge there to clean out. Also check to make sure the pushrods aren't clogged (they are hollow to let oil travel through them and to the rockers). If they are, you can clean them out or just go ahead and get new ones. +
 

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Discussion Starter #7
Great! I'll get to taking that carb off and havin' a look at it tomorrow. That book seems like quite an asset also, so I have ordered one from amazon.ca. Thanks again guys!
 

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1995 ETC, 75 Deville, Cad500 powered 73 Apollo, 94 Mark VIII
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Good luck, and I'm glad you got that book, you'll need it. A Quadrajet is NOT easy to rebuild, and not easy to tune for that matter. It's got all kinds of complex crap, but that's what makes it superior as a street carb...
 

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1976 Eldorado project
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Yeah I got the book with no clue about Quadrajets, rebuilt mine succesfully, tuned it succesfully. I love that book. I cheated this time around though...ordered a Stage 2 Quadrajet from JET Performance built for my engine :)
 
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