Go Back   Ford F150 Forum - Community of Ford Truck Fans > Late Model F150s > 1997 - 2003 Ford F150
Sign in using an external account
Register Forgot Password?


Reply
 
 
 
 
Thread Tools Search this Thread Display Modes
Old 07-08-2010, 08:31 PM   #1
Junior Member
 
Join Date: Jul 2010
Location: michigan
Posts: 14
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default 2003 5.4 engine misfire,HELP

Hi guys,
I am new to the forum.
My truck is a 2003 f150 with a 5.4 engine. It has a misfire on cylinder 4 and I cannot figure out the problem. It first started out this winter and would idle rough for abotu 30 seconds when started cold, after that it smoothed out and ran great. It eventually got worse this spring and started to do it everytime I started it. Now it has a misfire on cylinder 4 all the time and through the comlete RPM range.

I have done several things without an progress.

1. replaced coil and plug. Plug appears to be burning pretty good. Not wet at all. Could of had a slight whitish residue on part of the plug.
2. Swapped fuel injector from cylinder 1 and cylinder 4.
3. Checked compression and got 140 PSI.
4. Swapped coils around between 2 and 4.
5. Disconnected coil connector and truck ran much worse.
6. Disconnected fuel injector connector and truck ran much worse.
7. Pulled out PCV and truck did not idle any different or in the rpm range
8. checked hoses for vacuum leak and could not find any visually or by wiggling hoses around.


From here I am lost and don't know what else to do. If you guys have any ideas please let me know.

Thanks,
Kim
bluekim7 is offline   Reply With Quote
Old 07-08-2010, 08:42 PM   #2
Ninja Taco
 
C Denny Run*'s Avatar
 
Join Date: Sep 2009
Location: Covington Wa
Posts: 1,202
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

Cam position sensor(CPS) maybe?
__________________
UNITED WE STAND, DIVIDED WE FALL

~SUPPORT OUR TROOPS~
C Denny Run* is offline   Reply With Quote
Old 07-08-2010, 09:05 PM   #3
Member
 
Join Date: Apr 2010
Location: Everywhere
Posts: 4,124
Mentioned: 0 Post(s)
Thanks: 0
Thanked 8 Times in 4 Posts
Feedback Score: 0 reviews
Default

Vaccume leak somewhere....have you checked the whole system?
westtnfx4 is offline   Reply With Quote
Old 07-08-2010, 09:11 PM   #4
Junior Member
 
Join Date: Jul 2010
Location: michigan
Posts: 14
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

I have not had the system checked for a vacuum leaks. Can I do that myself or do I need to take it to a mechanic? I would like to avoid the dealership if possible.

Thanks,
Kim
bluekim7 is offline   Reply With Quote
Old 07-08-2010, 09:21 PM   #5
Member
 
Join Date: Apr 2010
Location: Everywhere
Posts: 4,124
Mentioned: 0 Post(s)
Thanks: 0
Thanked 8 Times in 4 Posts
Feedback Score: 0 reviews
Default

You can get a can of carb cleaner in a can and spray around everywhere...it will stall the engine if you have one....be carfull tho and don't start anything on fire please.
westtnfx4 is offline   Reply With Quote
Old 07-08-2010, 10:00 PM   #6
Junior Member
 
Join Date: Jul 2010
Location: michigan
Posts: 14
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

Thanks, I will try that tomorrow night and post what I find.
bluekim7 is offline   Reply With Quote
Old 07-09-2010, 07:30 AM   #7
OVERTHINKER
5 Year Member
 
torkum's Avatar
 
Join Date: Mar 2007
Location: MT. JULIET TN
Posts: 1,631
Mentioned: 0 Post(s)
Thanks: 0
Thanked 5 Times in 3 Posts
Feedback Score: 0 reviews
Default

What was the exact code you got? Could be a wiring issue to the COP.
__________________
2003 Supercrew 4X4





torkum is offline   Reply With Quote
Old 07-09-2010, 08:06 AM   #8
Ford Tough !!
 
drof 1's Avatar
 
Join Date: May 2010
Location: SC
Posts: 135
Mentioned: 0 Post(s)
Thanks: 0
Thanked 2 Times in 2 Posts
Feedback Score: 0 reviews
Default

Quote:
Originally Posted by bluekim7 View Post
I have not had the system checked for a vacuum leaks. Can I do that myself or do I need to take it to a mechanic? I would like to avoid the dealership if possible.

Thanks,
Kim
A vacuum guage/fuel pressure guage is not expensive & easy to use. I believe you should get a reading of 18 to 22 lbs, steady.
If code is saying # 4 misfire though I don;t believe it is vacuum, but stranger things have happened.
Also a stethoscope is only about $8 at autozone or advance auto. Not as good as a vacuum guage.
Have you checked your fuel injector?
drof 1 is offline   Reply With Quote
Old 07-09-2010, 08:09 AM   #9
Ford Tough !!
 
drof 1's Avatar
 
Join Date: May 2010
Location: SC
Posts: 135
Mentioned: 0 Post(s)
Thanks: 0
Thanked 2 Times in 2 Posts
Feedback Score: 0 reviews
Default

Quote:
Originally Posted by bluekim7 View Post
Hi guys,
I am new to the forum.
My truck is a 2003 f150 with a 5.4 engine. It has a misfire on cylinder 4 and I cannot figure out the problem. It first started out this winter and would idle rough for abotu 30 seconds when started cold, after that it smoothed out and ran great. It eventually got worse this spring and started to do it everytime I started it. Now it has a misfire on cylinder 4 all the time and through the comlete RPM range.

I have done several things without an progress.

1. replaced coil and plug. Plug appears to be burning pretty good. Not wet at all. Could of had a slight whitish residue on part of the plug.
2. Swapped fuel injector from cylinder 1 and cylinder 4.
3. Checked compression and got 140 PSI.
4. Swapped coils around between 2 and 4.
5. Disconnected coil connector and truck ran much worse.
6. Disconnected fuel injector connector and truck ran much worse.
7. Pulled out PCV and truck did not idle any different or in the rpm range
8. checked hoses for vacuum leak and could not find any visually or by wiggling hoses around.


From here I am lost and don't know what else to do. If you guys have any ideas please let me know.

Thanks,
Kim
After my previous post I came back to see what you had done, guess I should have first huh?
But you mention no difference when you pulled out the pcv. did you remove the pcv from the vacuum hose to see if you have good vacuum on the hose?
What does your check engine light code read? the actual code?
drof 1 is offline   Reply With Quote
Old 07-09-2010, 08:26 AM   #10
Junior Member
 
Join Date: Jul 2010
Location: michigan
Posts: 14
Mentioned: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Feedback Score: 0 reviews
Default

Quote:
Originally Posted by torkum View Post
What was the exact code you got? Could be a wiring issue to the COP.
I belive the code is P304 or PO304. I will find out today on my lunch at autozone.
bluekim7 is offline   Reply With Quote
Old 07-09-2010, 08:26 AM
 
 
 
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
2003 5.4 engine misfire bluekim7 Engine / Drivetrain Talk 8 08-09-2010 02:26 PM
Engine Misfire Scotty Usry 8 Cylinder Engines 4 03-23-2010 07:42 PM
Engine misfire F150 Texan General F150 Discussion 3 03-15-2010 12:46 AM
Help. Engine misfire? jazar10 Maintenance Shop 1 06-16-2009 10:08 AM
5.4 engine misfire? redman transport 2004 - 2008 Ford F150 11 01-11-2008 10:47 AM

Join F150 Forum

 

The Mustang Source
All times are GMT -4. The time now is 02:17 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2006 - 20011 F150forum.com
This site is in no way affiliated with the Ford Motor Company.