Thread: Carb question, losing it?

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I think I may be losing my mind. I have adjusted, readjusted, and re-readjusted my carb. I am heading toward re-re-re......you know where this is going. I have a reman (from chain auto supply store) manual choke quadrajet. I have adjusted the idle mixture about three times now. I am pretty sure I am doing it right. After I let the car sit for a day or two, it runs rich, really rich, I mean black spot on the driveway under the tailpipe rich. It acts like a stuck float. Does this type of carb have a conventional float? To set the idle mixture I have first set the timing and idle speed, then gently seated the idle mixture screws and turned them both out two turns. I then adjusted both screws in equal amounts unil the vacuum begins to drop and then back out 1/4 turn. Is this correct? If so, why would this thing run so rich every time I start it up after a day or two? It won't even idle without the "fast idle" linkage engaged, puffs black smoke, and runs like he**.

The choke has never been engaged. The choke "flap" (for lack of a better term) is always open all the way. I put my hand over the primaries to create a "choke" condition (just to see how this affected the way it ran) and my hand was wet with fuel pretty quick. How common is this?

The choke is always open?...Even on startup from cold? If so, no good. Here's how Ive done it, not to say its the only way, but works for me.....Choke the carb, warm her up to operating temp, then open choke fully. Hook up a vacuum guage to manifold vacuum and adjust idle mixture screws equal amonts to acheive highest possible vacuum reading (keeping idle around 800 rpm the whole time). Thats where you need to be. If still too rich, check your float level.

Yes!...had a rather successful weekend tuning my carb...stutter is pretty much gone after a bunch of tweaking...test drive...tweaking ...test drive. You know how it goes. Still no carb expert, but like to share what ive learned with others.

Thanks Nova and Denny (interesting website by the way) How does one check the float level on a qjet?

I'll give it a try, thanks. Some repair info I have read references a float gauge (C-4900) that is to be inserted in the vent hole (gauge floats in fuel when engine is idling). I haven't been able to find this gauge anywhere, has anyone heard of this?

i've found the quickest way to adjust carbs nowadays (in the shop at least) is to hook the car up to the 5 gas analyzer.... i get HC and CO levels just to about what spec says for smog laws and keep the idle to about what the book says depending of course whether its been cammed or what not... works like a charm.... can ussually get 'er tuned in about 5 minutes, test drive to be sure and be done..... if you dont have a smog machine though... kinda makes it difficult