miss firing issue

firststang · January 31st, 2011, 06:56 PM

i have a stock 2004 gt with 85,000 miles.i have only owened it a few days.it has a miss whenever its in a low rpm load or whenever i get bout half throttle.i have replaced all plugs and coil boots with no change.air filter is a little dirty but nothing major.service engine light is NOT on so scanner wont pick it up.any help would be great:

dark star · January 31st, 2011, 08:15 PM

Try swapping some known good coils on one cylinder at a time and see if that helps.

cliffyk · January 31st, 2011, 08:28 PM

A sticking EGR valve can cause this. My '03 started having those symptoms at 90k or so, I disabled the EGR in the tune and the problem went away.

This cost me about 1/3rd MPG as the EGR system does improve fuel economy at steady cruising speeds. This is not enough to cause me to buy a new EGR valve--someday when I get ambitious I will remove the valve and pipe and block it all off.

Mike113 · January 31st, 2011, 08:32 PM

I had a similar problem at around 60k miles. My engine would missfire and sputter etc. making the car buck a little at low rpms. What I ended up doing was getting all my injectors flushed, replaced one, and also had a coil or two replaced. I guess theres a few things it could be, but yours may need something similar.

Robber80 · January 31st, 2011, 10:03 PM

i have been chasing this same problem down for the last couple days. but after reading a crap load of threads that just end, i got no where. so i figured i'd chime in now that i fixed my missing problem. turns out that the coils can actually be working, but be week. sure enough we tested them with a tool from my buddys shop. heres the link of the tool to better describe it Waekon 76562 Test Equipment - Electronic Testing

had to coils that were week, replaced them and it was running smooth. but the idle was low and would almost stall. changed the IAC and it was back to normal. plus the car had a lot more power.

hope this helps.

firststang · February 1st, 2011, 10:04 AM

Thanx for all the tips.I will pick up a coil after work and start swapping it one at a time.makes sense

Mike113 · February 1st, 2011, 10:19 AM

Goodluck bro, and yea for me once I swapped out some coils I was good to go.

firststang · February 1st, 2011, 07:59 PM

its fixed.i bought 1 new coil and swapped one cylinder at a time and got it on 5th try.wow yaw was a huge help.thanx a million.now if i could just learn how to post pic of my car like yaw all got i would be set,lol

January 31st, 2011, 06:56 PM	#1
firststang Newbie 2004 Mustang GT Join Date: Jan 2011 Location: Hayden Al Posts: 18 Blog Entries: 1 iTrader: 0 reviews	miss firing issue i have a stock 2004 gt with 85,000 miles.i have only owened it a few days.it has a miss whenever its in a low rpm load or whenever i get bout half throttle.i have replaced all plugs and coil boots with no change.air filter is a little dirty but nothing major.service engine light is NOT on so scanner wont pick it up.any help would be great:

January 31st, 2011, 08:28 PM	#3
cliffyk Hardcore Enthusiast Join Date: Feb 2007 Location: Saint Augustine, FL Posts: 1,808 iTrader: 1 reviews	A sticking EGR valve can cause this. My '03 started having those symptoms at 90k or so, I disabled the EGR in the tune and the problem went away. This cost me about 1/3rd MPG as the EGR system does improve fuel economy at steady cruising speeds. This is not enough to cause me to buy a new EGR valve--someday when I get ambitious I will remove the valve and pipe and block it all off. __________________ -cliff knight- My Mustang 2003 GT, UPR X, 24lb/h injectors, Magnaflow, 180° stat, PP 70mm TB & plenum, DF Commando, Steeda UDPs, Ralco RZ_flywheel, RAM HDX clutch, WX EFX COPs 3.73s, 262 rwHP/305 lb-ft. Flex-fuel: burns gas and rubber...

January 31st, 2011, 08:32 PM	#4
Mike113 Regular 2000 Mustang GT 14.08@98 Join Date: Sep 2008 Location: Bradenton, Florida Posts: 439 iTrader: 0 reviews	I had a similar problem at around 60k miles. My engine would missfire and sputter etc. making the car buck a little at low rpms. What I ended up doing was getting all my injectors flushed, replaced one, and also had a coil or two replaced. I guess theres a few things it could be, but yours may need something similar. __________________ Built NA 2v with some goodies

February 1st, 2011, 10:19 AM	#7
Mike113 Regular 2000 Mustang GT 14.08@98 Join Date: Sep 2008 Location: Bradenton, Florida Posts: 439 iTrader: 0 reviews	Goodluck bro, and yea for me once I swapped out some coils I was good to go. __________________ Built NA 2v with some goodies

Threads Similar to: miss firing issue
Thread	Thread Starter	Forum	Replies	Last Post
carbed H/C/I 302 miss/sputter below 2k, and miss at 5k+	Silversixspeed	5.0 Mustangs	1	August 13th, 2009 09:54 PM
M-16 firing	WilltheThrill	The Clubhouse	9	March 4th, 2008 12:24 AM
miss firing	the tick	5.0 Mustangs	5	August 22nd, 2007 10:03 PM
firing	jonnotch	5.0 Mustangs	2	June 4th, 2007 05:04 PM
miss firing	hopper	5.0 Mustangs	31	May 30th, 2007 09:30 PM

January 31st, 2011, 08:15 PM	#2
dark star Regular 2000 Mustang GT Join Date: May 2010 Location: Alb, NM Posts: 216 iTrader: 0 reviews	Try swapping some known good coils on one cylinder at a time and see if that helps.

January 31st, 2011, 10:03 PM	#5
Robber80 Newbie Join Date: Jan 2011 Posts: 11 iTrader: 0 reviews	i have been chasing this same problem down for the last couple days. but after reading a crap load of threads that just end, i got no where. so i figured i'd chime in now that i fixed my missing problem. turns out that the coils can actually be working, but be week. sure enough we tested them with a tool from my buddys shop. heres the link of the tool to better describe it Waekon 76562 Test Equipment - Electronic Testing had to coils that were week, replaced them and it was running smooth. but the idle was low and would almost stall. changed the IAC and it was back to normal. plus the car had a lot more power. hope this helps.

February 1st, 2011, 10:04 AM	#6
firststang Newbie 2004 Mustang GT Join Date: Jan 2011 Location: Hayden Al Posts: 18 Blog Entries: 1 iTrader: 0 reviews	Thanx for all the tips.I will pick up a coil after work and start swapping it one at a time.makes sense

February 1st, 2011, 07:59 PM	#8
firststang Newbie 2004 Mustang GT Join Date: Jan 2011 Location: Hayden Al Posts: 18 Blog Entries: 1 iTrader: 0 reviews	its fixed.i bought 1 new coil and swapped one cylinder at a time and got it on 5th try.wow yaw was a huge help.thanx a million.now if i could just learn how to post pic of my car like yaw all got i would be set,lol

Remove Advertisements Sponsored Links
Ford Mustang Forum Advertisement

All times are GMT -4. The time now is 06:07 PM.
Contact Us - Modded Mustangs : Ford Mustang Forums - Privacy Statement - Top
Modded Mustangs is ©2005-2008, All Rights Reserved, And is Not Affiliated with Ford Motor Company. Forum is powered by vBulletin ©2000 - 2012, Jelsoft Ent. Ltd. & SEO by vBSEO 3.3.2 ©2009, Crawlability, Inc.