Motor is misfiring help? - 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 02-25-2005, 09:40 PM
Member
 
Join Date: Jan 2005
Location: Allen,TX
Age: 33
Posts: 51
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Motor is misfiring help?

Ok here is my problem my car has had a miss since the day i bought it. When it idles u can here it cut out it sounds like it is only one cylinder because it has a pause between cutting out. It also above 5,000 really starts to cutout and struggles to get up in rpms it gets poppity. I have ran 3 different top ends on this motor. First was the factory TPI. Second was a stealth ram setup. Third it is now carbed. Had 3 sets of wires 3 coils and 2 distributors. The motor is a 92 chevy truck 350 the guy before me rebuilt and i bought it with 2,000 miles on the motor. The guy put a small cam in it, XE262HR other than that the bottom of the motor was rebuilt to stock specs. Does anyone have any ideas as to what might be wrong?
Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
  #2 (permalink)  
Old 02-25-2005, 11:50 PM
Member
 
Join Date: Dec 2004
Location: Madison, WI
Posts: 1,885
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Are you sure the cam is not flat?
Reply With Quote Quick reply to this message
  #3 (permalink)  
Old 02-26-2005, 05:31 AM
willowbilly3's Avatar
Member
 

Last journal entry: Body mods
Last photo:
Join Date: Jun 2004
Location: Black Hills, South Dakota
Age: 61
Posts: 1,208
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Agree, sounds like a typical flat chevy cam. Could be a broken intake valve spring. Have you put a vacuum guage on it? Do so and note the readings A bad valve or valve spring with show as a sharp quick dip on the guage for every engine revolution.
Reply With Quote Quick reply to this message
  #4 (permalink)  
Old 02-26-2005, 07:03 AM
Member
 
Last photo:
Join Date: Nov 2004
Location: Indiana
Age: 60
Posts: 393
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
A broken intake spring wont make it miss. It will make it pop through the carb. A broken exhaust spring will make it miss. I had 3 broken springs 2 exhaust and 1 intake so thats where I got my info. Pull all the plug wires 1 at a time with it running. Watch a tach and see the difference. Is it just 1 cylinder? Does it move around? I would do a compression test. See if thats ok. If it has good compression and it comes down to 1 cylinder then you could have a broken spring, a bad cam lobe. or not getting fuel to that cylinder. The last one is not likely if your using a carb. If you suspect a spring try pushing the valve open by hand while its not running. On my motor the only ones I could move were the ones with broken springs.
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
305 Misfiring Silver_Camaro Engine 14 01-14-2004 09:17 PM
misfiring i think mustangman1968 Engine 2 12-09-2003 01:16 PM
What's the best way of checking for a misfiring plug Jag Daddy Engine 21 07-14-2003 10:53 PM


All times are GMT -6. The time now is 06:07 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.