gmc forums   gmc forums
Go Back   GMC Forums > GMC Vehicles No Longer In Production > GMC Jimmy Forum

GMC Jimmy Forum Forum for discussions regarding the GMC Jimmy


ATTENTION: We're looking for moderators. Is anyone interested?
GMC Forum: P0304 cylinder 4 misfire
Reply
 
Thread Tools
  #1  
Old 03-13-2012, 01:57 PM
shane.vattimo shane.vattimo is offline
Junior Member
 
Join Date: Mar 2012
Posts: 17
Default P0304 cylinder 4 misfire

Alright folks here it goes. cylinder 4 on gmc jimmy has a bit of a misfire and a slight of a rough idle. hesitation bog down when i stomp the accelerator. its a 99. spider injector is fine, we have a bright blue arc off plug and new plug wires. i have put a hose from even side of motor to ear and it is one of the smoothest motors i ever heard, not tick knock ping or chatter. how much does anyone know about back pressure affecting cylinder 4 misfire, on that side of the motor there is a small dent in exhaust pipe before the "y". please help...this piece has consumed my weekends for to long as i work a lot and have 2 small kids and a home renovation going on. wits end folks. somebody save me.
Reply With Quote

  #2  
Old 03-13-2012, 08:16 PM
shane.vattimo shane.vattimo is offline
Junior Member
 
Join Date: Mar 2012
Posts: 17
Default

any takers?
Reply With Quote
  #3  
Old 03-13-2012, 09:16 PM
Molson02536 Molson02536 is offline
Senior Member
 
Join Date: Dec 2009
Location: K/W Ontario Canada
Posts: 3,098
Send a message via AIM to Molson02536 Send a message via Yahoo to Molson02536
Cool

Quote:
Originally Posted by shane.vattimo View Post
Alright folks here it goes. cylinder 4 on gmc jimmy has a bit of a misfire and a slight of a rough idle. hesitation bog down when i stomp the accelerator. its a 99. spider injector is fine, we have a bright blue arc off plug and new plug wires. i have put a hose from even side of motor to ear and it is one of the smoothest motors i ever heard, not tick knock ping or chatter. how much does anyone know about back pressure affecting cylinder 4 misfire, on that side of the motor there is a small dent in exhaust pipe before the "y". please help...this piece has consumed my weekends for to long as i work a lot and have 2 small kids and a home renovation going on. wits end folks. somebody save me.
Start with the simple and clean your throttle body and your AMF sensor. With a dirty AMF sensor, it can cause the issues your describing and would not hurt also to give your engine a http://www.seafoamsales.com/ treatment.

Good luck and keep us posted.
Molson02536
Reply With Quote
  #4  
Old 03-20-2012, 09:11 AM
shane.vattimo shane.vattimo is offline
Junior Member
 
Join Date: Mar 2012
Posts: 17
Default

why is everyone all of the sudden trying to sell me seafoam. anyhew got crushed y pipe out runnin nothin but exhaust headers. back pressure is not the issue. wish it was. not plugs wires or injectors....i guess i gotta do like the rest of the schmucks and start swapping parts, which we know can get expensive. also distributor gear looks absolutley beautiful.
Reply With Quote
  #5  
Old 03-20-2012, 12:08 PM
shane.vattimo shane.vattimo is offline
Junior Member
 
Join Date: Mar 2012
Posts: 17
Default

cylinder 4 at 30 psi wet or dry.
Reply With Quote
  #6  
Old 03-20-2012, 09:20 PM
shane.vattimo shane.vattimo is offline
Junior Member
 
Join Date: Mar 2012
Posts: 17
Default

VALVE NOT SEATED PROPERLY! pulled the head stuck a vacuum to the valve and watched smoke pull in through intake port.
Reply With Quote
  #7  
Old 03-27-2012, 07:56 AM
shane.vattimo shane.vattimo is offline
Junior Member
 
Join Date: Mar 2012
Posts: 17
Default

70.00 in gaskets 80.00 in junkyard heads and she is runnin better then evr.
Reply With Quote
Reply

Tags
cylinder 4., p0304, po304

Thread Tools

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 -5. The time now is 04:49 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
gmcowners.com recognizes that "GMC", it's logos and various model names and numbers are registered trademarks of the General Motors Corporation. These terms are used for identification purposes only. gmcowners.com is not affiliated in any way with the General Motors Corporation, GMC or any other company listed herein. All information on this site is the opinion of its members and not the opinion of the site itself. 2014 Madison Ross Media Group. All rights reserved. Content published on GMCOwners.com requires permission for reprint.
MADISON ROSS MEDIA GROUP MARKETPLACE
Need products for your GMC Truck? Check out your options at the links below:

No special deals available at this time...