The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-04-2003, 03:26 PM   #1
frisky68
Registered User
 
Join Date: Sep 2002
Location: Plymouth, IN
Posts: 133
engine misfire question

i have a 69 step w/ a 327...HEI timing set to 8 deg. btdc...bosch +4 plugs...and a Holley carb.

My question is...under hard accel...usually around 3500 - 4000 rpm...there is a backfire coming from the motor...hard to tell if its in the exhaust or exactly where....what would be the most likely cause for this...thanks.Ken
__________________
94 K1500 SWB w/ 4" body and suspension lift
frisky68 is offline   Reply With Quote
Old 01-04-2003, 05:57 PM   #2
frisky68
Registered User
 
Join Date: Sep 2002
Location: Plymouth, IN
Posts: 133
anyone ??
__________________
94 K1500 SWB w/ 4" body and suspension lift
frisky68 is offline   Reply With Quote
Old 01-04-2003, 07:21 PM   #3
jamie72
Senior Member
 
jamie72's Avatar
 
Join Date: Apr 2000
Location: madison indiana
Posts: 3,839
maybe the your cam has a lobe worn round had one do that to me once,backfired throu carb thou.
good luck
__________________
jamie72
72 BB cheyenne -- Restoration getting started..

member #807



http://www.myspace.com/whitetailobsession
www.antlertalk.com
jamie72 is offline   Reply With Quote
Old 01-04-2003, 08:20 PM   #4
72K10
Registered User
 
Join Date: Dec 1999
Location: New York
Posts: 288
If it only happens under acceleration, I would say your carb's set too lean. Fuel starvation will cause a miss (not a backfire, though) under acceleration. Mine was missing under load and it was the fuel settings.
__________________
RLTW
70C10
72K10
72K10 Cheyenne
72C10 Cheyenne Super
72K10 is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not 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

Forum Jump


All times are GMT -4. The time now is 10:23 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com