Author Topic: carburator  (Read 3380 times)


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« on: May 07, 2007, 07:58:20 PM »
My car seen to be running to rich on gas, also went I start the car it smell strong on fumes, I also notice that went I punch the gas smokes comes out from the pipes, I believe I need to adjust the needles, can anybody help me with this, I am running a quadrajet made by edelbrock, and is a 600cfm. thanks


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Re: carburator
« Reply #1 on: May 07, 2007, 08:18:55 PM »
To adjust the idle mixture on most carburetors, begin with the idle mixture screw(s) turned out about one-and-a-half turns and the engine warmed up.  Adjust each idle screw individually in order to achieve the highest manifold vacuum (which should also be the highest idle rpm).  It is usually easier to get a more accurate vacuum reading as opposed to the idle rpm.  In any event,  a vacuum gauge and a handheld tach will allow you to set the idle adjustment properly.  If you have to turn the idle screws open more than 3-1/2 turns, I would be concerned about some other problem.

Also, a lot of ignition issues wind up being blamed on the carburetor because iginition problems can also cause the type of symptoms that you are describing - especially with ignition systems originally designed for leaded fuel which of course is a completely different beast from what you are putting into the tank today.  Make sure the timing is set correctly, that you have a strong coil, that you have good plug wires, no cracked distributor cap, good points and condenser, good rotor, etc, so that you are getting correct voltage to the plugs with the correct timing.
« Last Edit: May 08, 2007, 05:31:48 AM by rich69rs »
Richard Thomas
1969 RS


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Re: carburator
« Reply #2 on: May 08, 2007, 03:32:29 PM »
May I add to this, if you dont get much response from adjusting via needles, you may need to look at idle circuits metering rods or jets.    I work on holleys and that the way they work.   I do have knowledge of the older Carter AFB and AVS as they work much like the new Edelbrocks and they seem to work the same way.  They just dont have that troublesome rubber diaphram PV. 
Don Dabbs