All,

I was driving back from work yesterday and out of nowhere my truck jerked or missed 3 times. The RPM's did not change and in had no backfire. Then coming in today it happened 4-5 different times. I would let off the accelerator then go to speed back up and the truck would buck or miss again.
2004 F150 4x4 3V with 135,000.

Thank you,

Mike

 

most misfires are caused by a bad COP ( coil on top of the sparkplug). If it gets bad enough, you will get a code telling you which cylinder is misfiring. If it happens random, you may not have a code yet.

 

Steve, I have not gotten a code as of yet. Also, I have not changed plugs in 85,000 miles. Can I be losing a plug as well?

thank you

 

misfire can be due to plug, COP or fuel injector........ a bad COP is the most common. Plugs with 85K miles is the second best possibility. If you don't have a code, you can find someone with a better code reader that might be able to "see" the problem even tho it does not set a code.. Another method is to purchase a COP and change out #1 and run a day.. if it misfires, put the good COP on #2 and test for a day... etc.

 

I have been having the same issues the past couple weeks. I will be working on my truck this weekend so if you havent fixed it by then i will let you know how my project goes.. My truck through a P2006 code (Intake Manifold Runner Control Stuck Closed). I plan on taking the wires off and cleaning them and make sure they all look good, and will also do the spark plugs and coils just to get them all replaced as well as other minor stuff like fuel filter and cleaning all of my sensors and fuses. but plan on doing the wires first, then driving it to see if anything changes...then doing the plugs and coils and driving it again..

 

but plan on doing the wires first, then driving it to see if anything changes .......
. what wires ? What motor do you have ?

 

5.4V8.. Well i was planning on checking the wires that go to the intake manifold running control valve/maybe change actuator also idk, ive never fixed this problem just going by what ive read and giving it a shot....heard thats been an issue...and clean off the MAF sensor..

 

sorry........ I thought you ment spark plug wires !

 

Mine did this to me about 5-6 years ago. #3coil and #3 plug were both bad. I have the 4.2.. Never threw any codes, though. I guess I had it fixed before the computer had a chance to throw any codes. It has since been tuned up about 20,000 miles ago with new plugs and plug wires. The 4.2 does not use the COP design, but uses a separate coil pack. To date that's the only coil that's ever been replaced. The other 5 are still original. Only got 106k so I'm good for a while.

 

the 4.2 should have one coil, similar to what was common 20 years ago ........ but your right, one section could go bad and replacing the coil would fix that.

 

I had it done at the Ford dealer that I was using for service at the time before I moved out of the area. I remember they charged me over $300. Maybe they did replace the whole coil pack. What's an individual coil cost for the V8's?

 

dealer price for a single coil for the V8 is probably $100. To diagnose your V6 problem and change the coil, I would think $300. is accurate.

 

Yeah. Parts, labor, diagnosis charge. I guess that would be about right for my engine. Not that I was ever questioning it anyway. Thanks Steve. That was almost 6 years ago, too. Sometime 2010 if I remember correct. I know spark plugs on my V6 are pain in the butt to change because of the positioning of the motor in the frame. The rear-most plug on either side ends up being underneath the firewall.