Intermittent Misfire?
 

Hello everybody. I am having an issue with my 2005 Expedition 5.4L 3V. At a stop while in gear it will shake and when I start to accelerate it spits and sputters for about 500ft then clears up and runs great. It has thrown 2 codes, P0351 and P0356, so I replaced all 8 COPs and Plugs(broke 2 of them) but this didn't fix the issue and the same codes came back. I have tested the harness for COP #1 & #6 and I am getting 12-volts when the key is ON but the engine is not running. Any ideas would be greatly appreciated!!

Some additional info: 77,000 miles, new coils are Accel 140033, new plugs are Champion 7989, truck idles fine in Neutral or Park

Could be an injector issue. That engine has an extended warranty on the injectors 10 years 120k any problem caused by faulty injectors is covered.
Start with the basics swap coils with known good ones then injectors. if the miss remains pull the plug then compression test..

Had the same issue in July with a 99 4.2L and it turned out to be one bad injector.
Had my local dealer repair and replace to the tune on $760.00.
$30.00 part and the rest labor !

Thats just insane. No way labor should have been more then $200 for that.

Would the injector problem still throw the P0351 & P0356 codes and nothing else? That's the only reason I hadn't messed with the injectors before because the codes pointed me in the direction of the coils. Thanks!

Yes, Exactly. - Nail on the head :thumbsup:

You need those injectors replaced, ALL of them, pronto.

You don't wanna know what will happen if your don't. :eek: :help:

OK, all 8 injectors... I'm on it. ;):lol:

Well yesterday it started doing it even while sitting in Neutral and I started to notice a slight gasoline smell. I think I'm going to let the professionals handle it from here, to the dealer we go. :(

changing injectors takes longer to get the tools out and put back away than it does to change 'em

Any damage caused by injector failure is covered by ford for 10/120 on the 05 year. If your sure its injectors let ford fix it make sure they check everything else the cats etc. At some point if I had an 05 I'd want those injectors out. I dont think Ford covers that oddly enough. They would rather replace the damaged components then the injectors..

I just noticed he's running Champion's. Mannnn...

Well, the dealership should replace the injectors free. I don't know what their going say when they see the Champions in their lol.

He needs to bring in the injector letter, so the service rep knows the customer/owner is aware, -right from the start. Might prevent a hassle about the bill.

hopefully that works...



if not the campions are causing the misfire

I notice the Champions but didnt say anything about those because he's having the same misfires on the same cylinders so it is unlikely he put bad plugs in cylinders that had bad plugs..
Let us know how the Champions end up working out..

Yup, I read some comments about the Champions after I bought them but figured that the problem would move cylinders or at least go away for a little while.

I'll get that injector letter printed out to bring in with me, but do you guys think that's what is causing my problem or is that just something else to get taken care of while it's there?

It could be injectors. It could be something else to. Ask for it to be diagnosed ask what they charge for that up front. Dont mention the Ford letter until they do that.

Injector warranty
 

Is that injector warranty on any of the 5.4 engines or just from 2005? I have a 2000 ford thats now doing the same thing and im just a little under 120,000. Should i get the warranty and if so where do i get this warranty letter?