2004 4.6 dropping cylinders - Ford F150 Forum - Community of Ford Truck Fans

Topic Sponsor
2004 - 2008 Ford F150 General discussion on the 2004 - 2008 Ford F150 truck.

2004 4.6 dropping cylinders


Old 10-10-2017, 11:56 PM
Junior Member
Thread Starter
Join Date: Oct 2017
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Question 2004 4.6 dropping cylinders

Iíve got a 2004 f150 4.6, started missing so I changed plugs and coils, ran good for about a week then started acting up, some times you start it up and it idles fine and sometimes it idles rough, and when you drive it it runs good as long as you donít put the motor under any kind of a load, the more of a load the motor is under the worse it misses, as you start letting off the gas peddle you can feel the miss leaving and feel cylinders coming back,when you floor it down into passing gear itís like itís down to 3-4 cylinders and will barely pull itís self, I took it to the shop and computer showed misfire on cylinders and o2 sensors so I changed the 02 sensors but didnít help.

any ideas appericated guys
Jakob Donnally is offline  
Reply With Quote
Old 10-11-2017, 04:34 AM
Senior Member
gone postal's Avatar
Join Date: Jul 2009
Location: Central NY
Posts: 5,681
Thanked 250 Times in 186 Posts

Search FPDM on this site.

It's a module located above the spare tire which has a tendency to rot out. FPDM goes, or starts going, fuel supply to the motor gets screwed up.
gone postal is offline  
Reply With Quote
Old 10-12-2017, 06:58 PM
Junior Member
Thread Starter
Join Date: Oct 2017
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts

Well I put a fuel pump drive module on today and still same thing, also changed plugs again, and new fuel filter. Any more ideas what it could be
Jakob Donnally is offline  
Reply With Quote
Old 10-13-2017, 08:56 AM
650NutKase's Avatar
Join Date: Jan 2016
Location: Chuco Town, TX
Posts: 1,336
Thanked 145 Times in 137 Posts

Clogged cats
650NutKase is offline  
Reply With Quote
The Following User Says Thank You to 650NutKase For This Useful Post:
gone postal (10-13-2017)
Old 10-13-2017, 11:54 AM
SCORGE's Avatar
Join Date: Feb 2016
Location: Fort Mitchell, Al
Posts: 7,869
Thanked 579 Times in 462 Posts

Just to rebound on what 650 said, drive the truck for a bit...then go underneath and look at the cats. If one is glowing red, it's clogged.
SCORGE is online now  
Reply With Quote

Thread Tools
Search this Thread

Contact Us Advertising Cookie Policy Privacy Statement Terms of Service

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: