Just got my 350 in a week ago and i have been having some fun getting it tuned to my satisfaction.The engine seems to have a slight stumble at idle.When i put the thing in gear,it shakes and wants to stall if i don't give it some gas in a hurry.It get's alittle better when things warm up,but driveability sucks.I've put a rebuild kit in a early 80's quadrajet and thought the carb was at fault but now i'm not so sure.I've had it apart 3-4 times,reset the float several times,set the idle mixture,checked the jets(72's)even checked the main metering piston,everything looks good.I also took all choke gear off it so i know that isn't the problem.(Car is only run in the summer.)My last rochester was run like this and idled great and ran well.I had most of these parts on my other engine before it died of bearing failure(Heads,cam,intake,distributor)and it ran super.The only difference was the carb(i had to sell my edelbrock to buy the 350...)Do you guys think i might have a vacuum leak somewhere or a ignition problem?I've set the timing at 11-12 deg.and it pulls about 18 inches of vacuum just so you know.Thanks for listening.

 

18in/hg at idle should be okay, is it steady? If not, might be in the igition. Have you reverified the plug wire routing? I'd go over it again to make sure, especially on a newly installed engine.

 

Stock QJets run real lean on the idle circuits. Without a choke it takes FOREVER to warm the thing up- like ten miles of casual driving- before you can get an accurate picture of your tuning.

Also, make sure your idle speed isn't too high. Going from a 1200-1400 neutral idle down to 750 in gear will cause a bad stumble/stall. And make sure you check your initial timing with the vacuum advance disconnected and with the RPMs low engough that the centrifugal advance is NOT kicking in AT ALL.

If you want to fatten up the idle circuits on that QJet (more than just opening up the idle mixture screws- they don't go far enough usually) shoot me an email and I'll send you some step-by-step how-to.

 

Did some more road testing today and i still think it's the carb.To answer 8mike9,the vacuum is fairly steady and only drops slightly when the idle stumbles.The wires are routed correctly,but thanx for asking.Damon,I did set the timing with the advance unplugged and it was ideling at 850-900 rpms.I'm curious about the adjustments you suggest to fatten up the mixture.Please feel free to e-mail me at MTCAMARO@hotmail.com if you get a chance.The car is starting to come around alittle after the last tune session,it starts well after a few pumps on the gas,idels low at first,but idels too fast after it warms up.Driveability is much better,there used to be a dead spot at about 1500rpm which is pretty much gone.it still stumbles a bit at low idle,but not as bad.Does this indicate the mix is to lean?You guys are a big help,please keep it coming.We're real close!