Backfiring - Team Camaro Tech
Troubleshooting Diagnosing problems done here.

 
LinkBack Thread Tools Display Modes
post #1 of 4 (permalink) Old May 6th, 01, 07:47 PM Thread Starter
Gold Lifetime Member
Brian
 
btalbot's Avatar
 
Join Date: Mar 2001
Location: Pearland, TX
Posts: 25
Question

I've got a bored out 327 with stock cam, Q-jet on a stock manifold, stock distributor and coil, and cyclone headers. It was partially restored in the 1980's but has sat a lot recently due to job, family, and lack of dinero. I've have recently rejuvenated the restoration and have it running on the weekends. I have noticed a little irregularity in exhaust sound from the right bank and there seems to be some negative pressure at the right tail pipe. This side also has a significant backfire on decelaration at both high and low rpm's. Vaccum pressure gauge reading at the intake is 22 at an idle but has small regular drops to 17 or so. Think this is a sticky exhaust valve or similar problem. I do need to have the carb reworked, ignition and plugs repaced to eliminate them as a cause. Any other suggestions, ideas, or advice before I pull the heads?

Brian
btalbot is offline  
Sponsored Links
Advertisement
 
post #2 of 4 (permalink) Old May 7th, 01, 06:24 PM
Senior Tech
Dale
 
Join Date: Sep 2000
Location: Glendale,AZ.U.S.A.
Posts: 992
Post

Sure sounds like a bad valve.I would do a compression,and leakdown on that side.

------------------
68 z28 ,68 rs 327 ,73 454 vette, 2 goofy kids
dale68z is offline  
post #3 of 4 (permalink) Old May 8th, 01, 02:34 PM
Senior Tech
 
Join Date: Dec 2000
Location: Monroe, WA, USA
Posts: 312
Post

by back fire do you mean in the exaust pipe or through the intake.

exaust back fire is caused by a leak in the exaust system or a bad fireing cylender and un burned fuel geting into the exaust and igniting from the other hot exaust gas's.

intake back fire can be caused by a vacuum leak, timing problem, valve not seating, lean A/F ratieo, dirty carb, cam lobe's that are worn or flat, bad lifter.

hope this help's ya out! i would sugjest you do a good tune up and set the timing and clean out the carb or rebuild it and see how it dose. if it is still there look for a vacuum leak or exaust leak...good luck!

[This message has been edited by ilbl8 (edited 05-08-2001).]
ilbl8 is offline  
 
post #4 of 4 (permalink) Old May 8th, 01, 06:25 PM Thread Starter
Gold Lifetime Member
Brian
 
btalbot's Avatar
 
Join Date: Mar 2001
Location: Pearland, TX
Posts: 25
Post

ilbl8:

It's backfiring through the exhaust. I've got plans to pressure test the cylinders on that side as well as do a good general tune up. Then we will see were we stand. Thanks for all the info.

Brian
btalbot is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Team Camaro Tech forums, you must first register.
Please enter your desired user 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.
NOTE we receive a lot of registrations with bad email addresses. IF you do not receive your confirmation email you will not be able to post. contact support and we will try and help.
Be sure you enter a valid email address and check your spam folder as well.



Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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

 
For the best viewing experience please update your browser to Google Chrome