4 barrel carb question

[shortchevy84]

is my carb not working properly? i have the rochester quadrajet, and when everything is warmed to operating temperature, and i twist the throttle linkage all the way while the engine is running, the 3rd and 4th barrels don't open up. i can see it open maybe 1 or 2 millimeters, but my thinking was wide open throttle should pop those things wide open..?? i had the carb rebuilt last year, by a mechanic who is a complete you know what, screwed me over many differnet ways, but thats a whole nother story. so i'm thinking he possibly rebuilt it wrong or didn't fully put it back together correctly? i've had the carb off since then to sort of try and do some hands on learning about carbeurators, just seeing how everything worked, and i noticed the inner plates for the 3rd and 4th barrel work properly, but still the air cleaner plates barely open. anyway. i'm rambling. just an idea since my truck always seems to be starving for air. which way do i turn the idle mixture screws to lean it up? anyway, hope this makes sense. thanks for the help!

[shortchevy84]

hmm, i read that other post that seemed to be the exact same problem. i'd still like a little help to say exactly why it would only open a little bit, and how i would fix it. thanks

[Lt.Del]

One trick i used to do to see if the other two open up is this....if you have an auto trans, drive about 30 miles an hour while in low 2.  Then nail the gas.  You will be able to tell of the barrels kick in.  By putting her in low 2, you wont feel the passing gear kick in and fool ya.

SgtDel

[roundedline]

The quadrajet operates off of vacuum so it only opens the rear when it needs it.  It may be adjusted incorrectly.  If it isn't opening at all I would say it is adjustment that is needed.

I recommend tuning one with a vacuum gauge and adjust until max vacuum is achieved.

Here is some links for reading...
www.arkansaspontiacs.org/...Q-jets.htm
www.mako.com.au/buick/html/qjet_tips.htm
vetteworks.tripod.com/Qjet.htm
www.442.com/oldsfaq/ofcrb.htm

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[jo3y1nf4nt3]

could you direct me to some edelbrock performer series sites..i just bought the tuneup kit for the 1406 model carb...(ya know 600 cfm electric choke)  anyone have any tips/tricks to make it fun primo....(specs, L69 305 + .030, mild cam(notsure what kind of grind) and 2.73 rear (soon to be 3.73)....

i've been directing my funds here lately to my swb rather than my motorcycle.  

thanks for the helps....

[roundedline]

Are you wanting the same simular links I posted except for the Edelbrock carb?

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[jo3y1nf4nt3]

i really hadn't had a chance to read the linx since i have dial up....but yea.  something that'll give me some tips or tricks how to get the most oout of my edelbrock.  like i said, i have the spring kit coming in to hopefully give it alil more ummff....i just remember when i had it running in my truck, i was messing with the air/fuel idle mixture nuts and i'm not sure where they are.  i did get a write up (i believe on CHP on how to properly tune the carbs (holley, demon, edel/carter)  thanks yous guys..ima go outside and start the wrenching on my suspension parts that got done last week.  

Edited by: roundedline at: 11/9/05 10:47 am

[roundedline]

Try this:
mustangandfords.com/techa...index.html

Chris Lucas
www.73-87chevytrucks.com
www.captkaoscustoms.com
Project Su
Jimmy 2WD Project

[DnStClr]

What about this info from the Edelbrock site?-
www.edelbrock.com/automotive/eps_sect2.html

[TailGater]

dont the Rochester carbs have something in the choke to keep the secondarys closed untill the engine warms up? I wonder if maybe your choke is not fully opening and thus keeping the secondarys closed?

[shortbox85]

the carb on my 85 truck is a rochester Qjet and its shot, i had electric chokje on mine and the previous owner took it out completely and wired my choke wide open, my secondaries open wen i punch it, wen they open in low 2 the front shocks should lift up...but wen i kick them in the whistle like a turbo...thats pimp right there...to me ur vacuum sounds bad