i recently took my carb (cc q-jet) in to be rebuilt. needless to say they screwed it up.....bad. i took it bak 3 times with no luck and no refund. im only 17 and didnt exactly have another $300 to have sum 1 else re-do it the right way. so i bought a rochester tuning manual and decided to fix it myself. well for the most part i think i did a pretty good job considering my lack of quadrajet, (and carb in general) expirience.

so i thought i might come on here and ask a few questions to see if i can learn some things about these carbs....and help my car run alittle better...

right now the car idles smooth but has a slight flat spot off idle and seems to surge a bit under wot. i thought it may be the idle adjustment screws on the base plate...maybe turn those slightly in and open the throttle a little more to help transfer.... what are some good settings for idle screws (not mentioned in my manual), and why does the car surge? is close loop operation mixture (under full throttle)determined by the rich stop screw or what? please help, any info greatly appreciated

 

I know exactly how you feel. I had lots of problems with my carb and took it to be rebuilt. needless to say they fixed nothing and if anything made it worse. Ive dumped over $2500 into that carb and it still dosent run right. Like you i am also 17 and now broke. although youre probably better off considering you figured out how to tune it. By the way what is your ideling rpm? Also does your car hesitate upon heavy acceleration? Even though i know little; i have learned something in these 2 1/2 years with this demon car. I may be able to help; ive been trying to solve the same problems and have spent a lot of time researching.

 

the car idles at about 800 or so depending on how much idle bleed i put in. it only hesitates under wot, 3/4 or 1/2 throttle and its fine.

 

Well i think it sould be ideling at about 700. What kind of gas do you put in the car. I tried to put regular and even silver in mine and it started to backfire and hesitate worse than ever. Premium though expensive cleared up or nulled most of my problems.

 

What are your dwell readings? Idle mixture screw settings will help bring the dwell into range with the rich and lean stop settings. Does your manual cover this?

 

not really, i kno that dwell has to do with the cycle of the m/c soleniod, other than that i dont really kno what it reads on my car. i do kno that i have a new m/c soleniod so it should be working properly.....? i set the rich stop and lean stop to the factory settings in my manual, the idle air bleed and idle mixture screw settings are not mentioned, neigher is the idle speed setting. i thought that if i could get at least one of those 3 then i could figure out the others by trial and error. so far it seems like no matter what i do it runs to lean.......

 

You really need a dwell meter to properly set the carb. If you can't borrow one they're about $30. Unfortunately once you set it right you may never need it again.

Before you get one, set your idle mixture needles about 5 turns out (4 to 7 seems to work for most) and your air bleed four turns out. If the other settings are good you may be alright.

Does your torque converter lock up?

 

My rebuild kit said to set the idle mixture screws at 4-1/2 turns initially. That's where I set them, and that's where they're at now. Worked great that way to get the MCS dwell where it needed to be.

 

ya the converter locks like its supposed to . ill try those settings and let ya kno how it works

 

Converter lockup confirms that the electronics are working and that the TPS is good.

Try the settings and make sure you don't have ANY vacuum leaks. Pinch the hoses one by one with pliers while it's idling and there should be no change in idle speed or quality.

Maybe you can get it happy without using a dwell meter.