Hot Rod Forum : Hotrodders Bulletin Board - Reply to Topic
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine> 305 Quadrajet Rough Idle
User Name
Password
lost password?   |   register now

Thread: 305 Quadrajet Rough Idle Reply to Thread
Title:
  
Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Additional Options
Miscellaneous Options

Topic Review (Newest First)
02-04-2011 10:21 PM
jmabrao Really not looking forward to changing a torque converter
02-04-2011 10:00 PM
cobalt327 You can try to crutch it up by using more timing. I would hook the vacuum advance up to manifold vacuum to begin with.

Dial in around 18 degrees or so of initial, be sure the total stays below 36 degrees or so. You may need to modify the distributor to make this happen.

Lower the idle speed back down after using manifold vacuum, also readjust the idle mixture screws to give the highest vacuum/idle speed. This will help the idle to stabilize some.
02-04-2011 09:55 PM
American Muscle
Quote:
Originally Posted by jmabrao
Hey guys I am having trouble with my car idling rough. It is a 305 with a very mild 274H06 Cam in it. I have to have it idle at around 1000 rpm and when I put it in gear it slams down to about 600 and the car will literally shudder and shake. I have adjusted timing and idle fuel mix to no avail. You guys have any idea on how to smooth this thing out?
Shutter and shake, sounds like converter to me
02-04-2011 09:44 PM
cobalt327
Quote:
Originally Posted by jmabrao
It's been like this ever since I had it. it did the same thing wth the edelbrock Carb I had on it beforehand
I don't doubt it. The carb is not the root issue here- it's the torque converter.
02-04-2011 08:09 PM
jmabrao It's been like this ever since I had it. it did the same thing wth the edelbrock Carb I had on it beforehand
02-04-2011 08:00 PM
oldschool hero Did this just start doing it all of a sudden? Has it ran good in the past or have you just put it together?
02-04-2011 07:57 PM
hwcoop here is a great place if you need Q-Jet parts or tech info....he wrote the book on them!
http://www.cliffshighperformance.com/parts.html
02-04-2011 06:52 PM
cobalt327 The Q-jet IS a good carb, and Cole has it right- first the basics, THEN go looking deeper. More times than I care to recount, a busted vacuum hose has been the main problem.

But you won't be able to just bolt ANY carb up to a modded engine w/the stock settings and expect it to be perfect. Maybe one out of 20 times the carb will need nothing. The other 19 times, the carb will need opened up at least once- and possibly a dozen times- before it is dialed in 'perfectly'.

Besides the TC stall speed, some carb-related things that may need attention (by no means is this all-inclusive):

Rejetted
softer power piston spring
Different secondary rods and air valve spring setting
Enlarged idle port orifices


Good luck in any event.
02-04-2011 06:39 PM
eloc431962
Quote:
Originally Posted by cobalt327
It will take a looser torque converter. That may be a mild cam in a 350 but in a 305, it isn't.
Good call Cobalt. I didn't think about that.

Cole
02-04-2011 06:38 PM
cobalt327
Quote:
Originally Posted by jmabrao
Hey guys I am having trouble with my car idling rough. It is a 305 with a very mild 274H06 Cam in it. I have to have it idle at around 1000 rpm and when I put it in gear it slams down to about 600 and the car will literally shudder and shake. I have adjusted timing and idle fuel mix to no avail. You guys have any idea on how to smooth this thing out?
It will take a looser torque converter. That may be a mild cam in a 350 but in a 305, it isn't.
02-04-2011 06:09 PM
eloc431962 If you are not real good with a q-jet you probably need to find someone that is IMHO especially if you been tweaking on it. They are great carbs when they are good but if they need work you need to know what you are doing when it comes to a q-jet carb. JMO

Cole
02-04-2011 05:14 PM
jmabrao Yep I tried that and squirted everywhere its a no go no change at all.
02-04-2011 04:06 PM
eloc431962 Take some carb cleaner and spray around the base of the carb and anywhere around it that it could have a vacuum leak, And see if the idle changes when spraying these places. if it changes you have found a problem spot.JMO
It should smooth out if you hit a leak with the spray.

Cole
02-04-2011 03:59 PM
jmabrao I couldn't find an exhaust leak anywhere I even plugged all the ports up.
02-04-2011 03:58 PM
eloc431962 Check around the base for a vaccum leak. JMO


Cole
This thread has more than 15 replies. Click here to review the whole thread.

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


All times are GMT -6. The time now is 09:19 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.