backfire from carb - 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 02-25-2006, 02:40 PM
TASHAN's Avatar
Member
 
Join Date: Aug 2003
Location: dania beach,. Fl
Age: 34
Posts: 49
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
backfire from carb

Im having a problem getting my engine to run. Everytime I start it it backfires out of the carb. I had a BG demon on it that was new and it ran ok a few times and then this started happening. So i had it rebuilt with new powervalve and it still happens. then I put an edelbrock on there and it still happens no matter the timing location on the distributor. I checked all the valve lash and spark. The only thing I can think of is cam timing, but it ran ok when first rebuilt. Another thing to add is if I get it up to about 160 degrees or better it begens to run ok. Im lost. any suggestion?

    Advertisement
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-25-2006, 02:43 PM
poncho62's Avatar
Out of the Loop Moderator
 
Last wiki edit: Streetbeasts links
Last journal entry: at car show
Last photo:
Join Date: Oct 2003
Location: Hanover, Ontario, Canada
Age: 62
Posts: 16,857
Wiki Edits: 5

Thanks: 20
Thanked 246 Times in 200 Posts
Sounds like you have a broken rocker arm, or bent pushrod....on the exhaust.
__________________
Ontario Rodders
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-25-2006, 03:19 PM
TASHAN's Avatar
Member
 
Join Date: Aug 2003
Location: dania beach,. Fl
Age: 34
Posts: 49
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
yea maybe a bent rod. Ill probly have to tear it down to see if my pistons are tapin the valves.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-25-2006, 03:50 PM
poncho62's Avatar
Out of the Loop Moderator
 
Last wiki edit: Streetbeasts links
Last journal entry: at car show
Last photo:
Join Date: Oct 2003
Location: Hanover, Ontario, Canada
Age: 62
Posts: 16,857
Wiki Edits: 5

Thanks: 20
Thanked 246 Times in 200 Posts
Just take the valve cover off.....You will see right away if thats your problem. What may be happening, is that the exhaust valve isn't opening, so the exhaust gasses have nowhere to go, but back up through the carb.

Make sense?
__________________
Ontario Rodders
Reply With Quote Quick reply to this message
  #5 (permalink)  
Old 02-25-2006, 04:03 PM
docvette's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Rebuild an alternator Last photo:
Join Date: Mar 2004
Location: Lafayette, california
Age: 62
Posts: 7,362
Wiki Edits: 12

Thanks: 0
Thanked 6 Times in 3 Posts
Doc here,

What Ignition System do you have?

Doc
__________________
Aftermarket Solutions
Electronic & Electrical
Innovations
Reply With Quote Quick reply to this message
  #6 (permalink)  
Old 02-25-2006, 04:08 PM
TASHAN's Avatar
Member
 
Join Date: Aug 2003
Location: dania beach,. Fl
Age: 34
Posts: 49
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
Mallory HEI
Reply With Quote Quick reply to this message
  #7 (permalink)  
Old 02-25-2006, 04:20 PM
docvette's Avatar
Hotrodders.com Moderator
 
Last wiki edit: Rebuild an alternator Last photo:
Join Date: Mar 2004
Location: Lafayette, california
Age: 62
Posts: 7,362
Wiki Edits: 12

Thanks: 0
Thanked 6 Times in 3 Posts
Doc here,

Try this,

On a dead cold engine, using a heat gun, or (if you have lots of time) a Hairdryer, heat the base of the dizzy up to about 180..then try and start it, If it runs better (as it did on a warmed up engine) replace the module.

CHECK AND DOUBLE check to see 5 and 7 aren't reversed too..It will cause this exact problem. and their the ONLY two wires that are next to each other on BOTH ends..HAND OVER HAND them to be sure they are correct.

Stuck Valve or over adjusted as poncho said will do the same thing too..Check that with a Vacuum gauge, Should be 17 to 20 In HG at idle with NO needle flucution..If the needle is all over the map..check your valves.

Doc
__________________
Aftermarket Solutions
Electronic & Electrical
Innovations

Last edited by docvette; 02-25-2006 at 04:22 PM. Reason: bumbling bigthumbitis..most used key..backspace
Reply With Quote Quick reply to this message
  #8 (permalink)  
Old 02-25-2006, 05:05 PM
TASHAN's Avatar
Member
 
Join Date: Aug 2003
Location: dania beach,. Fl
Age: 34
Posts: 49
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
ok, thanks very much for the help.
Reply With Quote Quick reply to this message
  #9 (permalink)  
Old 02-25-2006, 06:26 PM
97Z28's Avatar
NTI Grad.
 
Last photo:
Join Date: Jul 2005
Location: Chardon, Ohio
Age: 32
Posts: 607
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
it could also be a stuck valve too... not opening or closing the way it should...
Reply With Quote Quick reply to this message
  #10 (permalink)  
Old 02-25-2006, 08:05 PM
TASHAN's Avatar
Member
 
Join Date: Aug 2003
Location: dania beach,. Fl
Age: 34
Posts: 49
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
I just remembered something, when the motor was running good,. I ended up shorting the old A/C compressor hot on the frame and cooked the rubber right off it and the alt. wire, once I fixed that wire was when it started running like crap,. would that short have effected the ignition module? It wasnt like just a pop it was shorting on it for probley about 10-15 seconds.

Last edited by TASHAN; 02-26-2006 at 07:19 AM.
Reply With Quote Quick reply to this message
  #11 (permalink)  
Old 02-26-2006, 08:52 AM
TASHAN's Avatar
Member
 
Join Date: Aug 2003
Location: dania beach,. Fl
Age: 34
Posts: 49
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
I guess Ill just replace it anyways. Ill bet thats what happened.
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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Small backfire from Carb...Chevy 350 interro1 Engine 7 07-15-2005 02:00 PM
Need Help with my carb mighty demon 1985fiero Engine 10 06-08-2005 03:24 PM
Holley carb has me at wit's end cool rockin daddy Engine 23 06-02-2005 02:38 PM
Need help with Edelbrock carb Crazy-J Engine 1 06-01-2005 02:24 PM
backfire in carb? help? unibrowarrior Engine 26 08-27-2003 08:42 PM


All times are GMT -6. The time now is 04:38 AM.


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.