ok, i posted in the v10 forum but thought it would post here also and maybe get some ideas...i'm at a serious loss of what to do here.


i changed plugs last night, kept the stock coils/boots. now i have a miss under load 1500-2k. i bought a new coil and swapped it out with every frigging coil and nothing changed. same miss in the same rpm range.

wtf? do i need to just buy all new coils? pull the plugs/replace the new plugs again? i'm so pissed.

heres the other post
https://www.ford-trucks.com/forums/9...w-missing.html

 

I don't think that I can help you diagnose the problem more than you have done, except to ask if there are any codes showing up on a scanner.

It might be a electrical issue, but how is the fuel system? One of the injectors may be performing sub par or dirty. Mine does that sometimes and starts a minor stumble in the engine. It just happened again a few weeks ago. I found that Techron concentrate works absolute wonders. 2 bottles of the 20 gallon size in a tank of gas does the trick.

 

Did you have a miss before changing the plugs?

You could have more than one coil going bad.

 

no it was running perfectly before, i wish i woulda left well enough alone.

yeah i have thought of the chance of more then one COP going bad. but wouldnt it get alittle better if the new one was in place of one of the bad?

i did get one code P0356 Ignition Coil F Primary/Secondary Circuit Malfunction but that may have been from me disconnecting the coil trying to find which one it was.

are these coils really that sensitve that pulling them to change plugs would make it go bad?

i'm debating on pulling all the plugs and putting the old ones back in and seeing what happends. im getting desperate and dont want to if i dont have to shell out $150 for 10 new coild if i dont need them. i just did balljoints last week and that took a huge chunk out of my savings.

also i've calmed down, my mom ended up giving me one of her calming/relaxing meds because i was freaking out. i'm muuuuch more relaxed now trying to think of how to fix this rationaly now.

 

If all was fine before changing plugs my guess it's not a COP issue, so step back and recheck all connectors/plugs and wiring to be sure there is no loose connections, bent pin in connectors or nothing else got knocked loose around the area you were working on each cylinder. It's not a process that should be rushed so take your time.

 

Has it been raining there? Water in the plug holes?

 

I agree with putting the old plugs back in. It will justify spending the money even though it will take a little time to do. Since that was the only change, it will be good to eliminate it as a problem. Good luck.

 

Check each "New" plug as you take it out. maybe got messed up putting it in. dirt, bad gap, etc.

 

It's almost impossible for 2 cops to go bad at the same time (no, not those cops), and it's extremely rare for a new plug not to work. Did you drop 1 and close the gap? Check all your connections. A cop won't go bad as soon as you change your plugs. That is extremely rare also.
Cops usually go bad when money is envolved

 

That's what I was thnking....

 

nope no rain yet..we're still getting alittle snow here and there but the truck is garaged at night and doesnt sit out much. the plug holes were nice and dry no dirt or anything in them. allthough there was a bunch of walnut shells up by them between the valve covers..musta been when she spent her time in CT as we do not have walnut trees here.

ok i'm gonna pull them tomarrow before i go buy anything else. one by one check the gap on each of them as i'm human and coulda dropped one the wrong way or somthing after setting them. i'm hoping so..after being without my truck last week and driving my f-250 i was looking forword to driving the big red beast!

i'll report back tomarrow, last night and today was just very stressful.

 

Wait a minute. A few years ago I took a trip with the family to Maine with a 1999 Expedition with the 4.6 L V8. The engine started missing only on one cylinder in a certain RPM range and I was going nuts for two days trying to figure it out in a hotel parking lot. I had replaced the plugs just before the trip. I replaced the wires, (it had two coil packs) and was even ready to replace the coil packs.

In desperation, since I did not have any of my garage tools, I took it to a Mineke as they were the only thing open,.
It was Sunday, and they took their time with it. I'll be durned if they didn't find a plug with a cracked ceramic insulation. I could barely see the crack when held up in bright sunlight. They replaced that plug, and it fixed the problem for good. They only charged me $20. God Bless 'em.

Anyway, just an idea to check.

 

Cops are a pain in the **** ............. oh wait......... i am a retired cop. you mean there was money to be had. what would i have to do? Maybe have my gap rechecked? see if i have sparke? what?

 

Bion has a very good point about a plug having a cracked insulator this can happen very easily even before you purchased.

 

i'm pretty sure it was a bad plug, autolite double plats btw.

i cleaned and replaced all the old factoy motorcraft plugs which looked in great shape for 95k miles and bam, she runs smooth as glass and pulls hard like she allways has..not skipping a beat.

moral of the story, maybe in 20-30k miles i'll attempt plugs again. with motorcraft plugs. i'll also pick a less stressful time to take on the project as to not get stressed out like i did.

only upside is i can now change a coil in about 45 seconds lol