General Maintenance & Repairs Leaks | Squeaks | Clunks | Rattles | Grinds

Misfire source?

Old 04-15-2006, 04:37 PM
  #1  
On The Tree
Thread Starter
iTrader: (1)
 
98Z28MrO's Avatar
 
Join Date: Feb 2004
Location: Richmond, VA
Posts: 177
Likes: 0
Received 0 Likes on 0 Posts

Default Misfire... ?

I have a misfire trouble code popin up. So far ive changed 7 out of the 8 plugs and the wires are not that old. What are the chances that the 8th plug is causing it? Also, what are some other possible causes for the problem?

Thanks
Bryan
Old 04-16-2006, 12:46 PM
  #2  
On The Tree
 
Billy177's Avatar
 
Join Date: Mar 2005
Posts: 133
Likes: 0
Received 0 Likes on 0 Posts
Default

about a 1 in 8 chance that it is causing the misfire.

i would make sure all the plugs and wires are good then check for any vaccum leaks or anything like that
Old 04-16-2006, 12:54 PM
  #3  
On The Tree
Thread Starter
iTrader: (1)
 
98Z28MrO's Avatar
 
Join Date: Feb 2004
Location: Richmond, VA
Posts: 177
Likes: 0
Received 0 Likes on 0 Posts

Default

haha i was thinkin more like 1 out of 24..
Old 04-16-2006, 01:02 PM
  #4  
TECH Resident
iTrader: (21)
 
camaroguy26's Avatar
 
Join Date: Sep 2005
Location: New Jersey
Posts: 820
Likes: 0
Received 0 Likes on 0 Posts
Default

just go to autozone to have the codes scanned. They'll do it for free if you have a light coming on. It will show which cylinder is misfiring. It could be a plug that is cracked, the wires are loose, maybe even the coil failed. It does happen, very rare for a coil to fail but who knows.
Old 04-16-2006, 02:53 PM
  #5  
Banned
 
BLKWS.6's Avatar
 
Join Date: Dec 2004
Posts: 2,636
Likes: 0
Received 2 Likes on 2 Posts
Default

make sure the wires "click" when you put them on. Sometimes they can be a booger on my 5.0 to get em' to snap.
Old 04-16-2006, 03:28 PM
  #6  
On The Tree
Thread Starter
iTrader: (1)
 
98Z28MrO's Avatar
 
Join Date: Feb 2004
Location: Richmond, VA
Posts: 177
Likes: 0
Received 0 Likes on 0 Posts

Default

I have hp tuners which is why i know what the code is... but i didnt think it showed the cylinder number with the code.. Maybe i just didnt pay enough attention.. I have a feeling its one of the wires, i just need to double check if they are clicked or not.

Thanks for the help guys.
Bryan
Old 04-16-2006, 04:03 PM
  #7  
Banned
 
BLKWS.6's Avatar
 
Join Date: Dec 2004
Posts: 2,636
Likes: 0
Received 2 Likes on 2 Posts
Default

FYI, i had a crown vic with a 5.4L motor out of a 98 F150. When we first ran it around hte block, it was raining. wouldnt even spin a tire...we replaced all the plug wires and it would spin em pretty mean in the rain and ok in dry weather if you tq braked a little. plug wires gave it at least 30-50 on the low end. HUGE difference, dont discount that a plug wire may be broken inside.
Old 04-18-2006, 06:36 PM
  #8  
TECH Regular
iTrader: (2)
 
Travis99LS1's Avatar
 
Join Date: Feb 2006
Location: NC
Posts: 427
Likes: 0
Received 0 Likes on 0 Posts
Default

Dont forget it doesent have to be ignition related to cause a misfire....It could be a misfire from an overly rich condition in a cylinder...or it could be a misfire from an overly lean condition....it could be mechanical misfire....You really need to look at some stuff on a scan tool, or an exhaust analyzer to get a better idea of the possible causes..


Thread Tools
Search this Thread

All times are GMT -5. The time now is 08:00 AM.