06 expy #2 cyl misfire

[jjford]

Hey,

New here but have read a lot.
Got a problem with the #2 cylinder misfiring.
Here's what is happening. Whenever I go up a slight grade and give it just enough gas to keep speed without forcing it to downshift, it starts to misfire and lose power. If I keep on it a little to keep going, I get the 0302 code, #2 cylinder misfire. So I replaced the coil pack, no fix. Replaced plug, no fix. Replaced all coil packs, including #2, no fix. Replaced fuel filter and all injectors, no fix. Checked #2 coil wire with NOID and said it was OK, got the flash. However, the set I rented from Autozone wouldn't fit the plug to the coil. Had to use the GM NOID out of the set. Had it at a shop and they "said" the compression was good on #2. I have also recently cleaned the throttle body and looked for any bad connections. the one thing I haven't checked yet is the fuel pressure. Probably should, but it runs fine on even grade and idle.

Fuel issue, vacuum leak, intake leak, ???

One other note that this may help with is that I have a ticking in the engine. Sounds like a lifter. Could a rocker be loose, bad lifter, bent valve? These are all options I have to address but it just seems like this should be less harder.

Out of options for my wallet.

Help!!

Any help would be appreciated.

Thanks

 

[CARO'S98EB]

Recheck coil#2 swap with another. if still cyl 2 then recheck the plug. with a miss under load it is almost certainly and ign miss.

 

[KC Dave]

Ticking may be Cam Phasers, which is an expensive fix..

As for the misfire, does it feel / act like a bad plug wire? I know you replaced the COP and the plug, but did you replace or examine the boot between the Coil and plug? If the boot is torn or otherwise damaged, perhaps it is breaking down under a load causing a miss? You already did what I would have done, so just throwing that out there. Other than that, if it had a burnt valve or vaccuum leak, I would think it would be tripping a code for Lean or Rich fuel mixture.

 

[jjford]

well, it's got a new cop so the boot and all is good. Checked them before installed them. Am also starting to wonder about a broken/loose rocker. Whaddya think?

 

[CARO'S98EB]

if the rocker was off it would miss all the time.

 

[Old Guy]

If the fuel pressure as low, the reader would say "fuel pressure low, bank 1" (had this on mine)

I chased my tail for a couple of hours on a simular problem. On ALL other manufacturers, #1 is on the left front side of the engine. On Fords, its on the right front. Turned out to be the coil.

 

[jjford]

I'll swap coils. But with all 8 being new and installed I find it highly unlikely, but possible, that I got a bad one from the store and happened to put it on #2. Am positive about the passenger side being 1-4 cyls since I messed this up once before. Am starting to wonder also that my reader is probably an older generation OBDII reader, could it not pick up all the codes? Had an air cleaner intake come apart on my Windstar one time and MAF got all confused. Van acted kind of same as now. But the Expedition isn't showing any codes besides the misfire. How can I check the MAF? My manual only shows a 4 pin MAF whereas mine is 6 or 8.
Thanks for the rocker info too. That makes sense.

 

[jjford]

OK. Finally broke down and took to dealer. Was wondering if my OBD was catching all the codes. Told dealer what all I did. I was at a loss at this point. He told me that the #6 plug was loose causing the misfire. If you look up the firing order, 1-3-7-2-6-5-4-8 for the 5.4L, it makes sense that the #6 cylinder could could cause #2 or #7 to misfire. The mechanic did tell me though that all the work I did to it was good as they would have probably done it anyway. They also told me that since the plug was loose, I was pretty close to blowing the m-fer out causing more severe damage as many of you know. Now I just had all the plugs changed at a different dealership about six months ago (25K mi), so when I pick the truck up in the morning Friday, am going straight there to raise hell.
They said they drove the truck after clearing all the codes and said it runs like a scalded dog. We'll see.
Post again tomorrow after I drive it.
Thanks to all for the input. Was helpful.

P.S. Glad I didn't spend $ on the MAF like I was thinking!!!!

 

[jjford]

Okay. just got home a little bit ago. Took the long way home so I could put it under load on some hills and test her out. She's runnin' like a champ!! As for the ticking I mentioned in the original post, that's gone now too!! I couldn't be any happier at this point. It's almost as if she's good as new.

I also had a guy tell me that some mechanics and dealers won't torque down the plugs to the required spec since they are afraid of stripping out the aluminum heads or are worried about removing them in the future. So I would recommend that if you have your plugs done or do them yourself, use some anti-seize compound on the threads and torque down properly.
So my lesson learned is that no matter how hard you try to fix something yourself with all the advice you can get from so many people, it's probably just best to do what you can then go to the dealer. I got so much misinformation from several mechanics, people at work, parts stores, etc that I think I was over-thinking the problem and didn't start with the basics. I learned a lot on this one, paid the prices, but was worth it all.

Thanks again for all your help and I hope this info helps somebody out if the they have a similar problem.

 

[CARO'S98EB]

glad to hear it!