carb question - Hot Rod Forum : Hotrodders Bulletin Board
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
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 03-14-2004, 05:40 PM
New Member
 
Join Date: Sep 2003
Location: illinois
Age: 38
Posts: 29
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
carb question

i just put a 625 road demon on my 82 trans am with a 305 problem im having is when i shut the car off it will run on and sputter then it dies also when i put my hand on top of the carb it dies right away is this supposed to happen or is it a sign of a lean condition or something else thanks for any help,steve
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 03-14-2004, 05:51 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,643
Wiki Edits: 0

Thanks: 13
Thanked 56 Times in 53 Posts
Did you read the instruction book that came with the carb? in the troubleshooting area, it tells why it would do this, Demons aren`t bolt on and go carbs, they have to be set up properly, otherwise the results are not good, read the instructions very very closely, then try again.
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 03-14-2004, 07:59 PM
New Member
 
Join Date: Sep 2003
Location: illinois
Age: 38
Posts: 29
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
ya know maybe the thing didnt come with a book or maybe i misplaced it whatever the case maybe i was just asking for some help now maybe i took your post the wrong way its been a long day but...seems like your jus beein ignorant whenever someone asks me a question im more than happy to answer it for them if i dont want answering it i dont i just shut my mouth its that easy
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 03-14-2004, 08:40 PM
Member
 
Last photo:
Join Date: Feb 2004
Location: Los Angeles
Age: 31
Posts: 67
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Uhm... I don't think DoubleVision is trying to be ignorant. He is usually very helpful and I think he is just trying to give you a quick tip. Maybe he doesn't use any of the BG Demon carbs and might not know much about them. I am really looking into getting a Race Demon and I thought his tip of careful tuning was helpful.

Well, it sounds like your car is dieseling. Obviously the ignition is cut because you have turned it off at the source (Key), but the car is still trying to run without any spark. It is pulling in enough air/fuel that it can continue to run because the engine is warm enough to light the mixture. Have you tried to make any adjustments after your initial setup? Maybe you should give it a quick once over and double check everything.
Here is a note I pulled from another site:

What is happening is that the throttle is remaining partially open when the engine is shut down, which gives the hot engine sufficient fuel to run without a spark from the spark plugs. Most hot engines have sufficient carbon build-up that remains glowing red hot and acts as an igniter for the fuel. The solution is to make sure that the throttle closes completely when you turn off the ignition switch. Check the throttle stop and make sure that the fast idle on the choke or the "bottom stop" isn't what is stopping the throttle from closing.

I don't know if this will help, but you should be able to find more help in the knowledge base or through an online search engine. Hope you get it solved easily...
Rick
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 03-14-2004, 08:44 PM
Member
 
Last photo:
Join Date: Aug 2002
Location: Alabama
Posts: 592
Wiki Edits: 0

Thanks: 0
Thanked 4 Times in 4 Posts
Lower the idle speed

Generally that run on condition is caused by the idle speed being too high. I would adjust the two idle screws first so that you get the highest RPM when the engine is idleing, then adjust the idle speed a little lower than what you have now. 600 rpm is a good rule of thumb to start with.

If you completely covered the carb with your hand, it is normal for the engine to stop right away. If you partially closed it off and it stopped right away that is unusual.
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 03-14-2004, 08:50 PM
New Member
 
Join Date: Sep 2003
Location: illinois
Age: 38
Posts: 29
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
hey thanks for all the help guys and doublevision if i did take your post the wrong way i apologize
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 03-14-2004, 10:55 PM
DoubleVision's Avatar
Not Considered a Senior Member
 
Last photo:
Join Date: Oct 2002
Location: Heart Of Dixie
Age: 40
Posts: 10,643
Wiki Edits: 0

Thanks: 13
Thanked 56 Times in 53 Posts
No problem. The book that came with my Road Demon 625 says, Runs On After Shut off - Reset butterflies, lower idle RPM, Check spark timing.
What I was referring to was, when I got my demon, I learned real quick I couldn`t bolt it on, turn a few screws and go. I picked up the book and went step by step, and it`s been right ever since. Demons are real precise, not like a holley or any other carb I`ve used, they have to be on the money or close to on the money or they won`t operate right. it also says to set the secondary butterflies to where you can`t see any of the transfer slot, but will the very second they open, it says for a baseline, set the primary butterflies at .025
If you didn`t recieve a book with your Demon, call Barry Grant or send Tech@BG on this site a private message, they`ll be more than happy to send you one. They did me when I lost mine. Hope this helps.
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 03-14-2004, 11:25 PM
New Member
 
Join Date: Sep 2003
Location: illinois
Age: 38
Posts: 29
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
thanks i appreciate it ,my idle is set at about 850-900 in park and 750 in drive is this too high? i noticed hotrodman said 600 is that in park or drive
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 03-15-2004, 08:09 PM
Member
 
Last photo:
Join Date: Aug 2002
Location: Alabama
Posts: 592
Wiki Edits: 0

Thanks: 0
Thanked 4 Times in 4 Posts
600 rpm is in drive, but this is just a rule of thumb. I have seen some cars that worked fine at 500 and others better at 700.
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 03-15-2004, 08:22 PM
FASTCHEVY's Avatar
RatRod B4 RatRods were Cool
 
Last photo:
Join Date: Feb 2004
Location: Dallas Texas
Age: 31
Posts: 800
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
I can have mine idle at 800 or 1000 RPM in park, but it will always idle at 500 rpm in drive. don't know why.
Reply With Quote Quick reply to this message

Recent Engine posts with photos

Quick Reply
Message:
Options

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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
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.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

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
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 07:58 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.