I replaced my cops after 100,000 miles because one of mine went and I figured it was time for new ones. I bought the motoblues a month ago and the truck ran fine. As soon as the Temp outside started to drop below 60 degrees the truck would start to miss and threw a P0355 code at me for Ignition Missfire. When the truck would warm up it would clear up fine and run on all 8 cylinders. I've tried emailing RPM outlet and calling them but I cant get a hold of anyone. Has anyone had any similar issues like this? Any way of telling which cylinder code P0355 would be? I know its not the plugs because I replaced them with Iridiums 10,000 miles ago and the miss started after replacing the COPS.

 

That should be cylinder number 5 I believe that would be the first one on the driver side, did you use dielectric grease when you installed them??

 

P035X indicates there is an electrical fault in the primary coil circuit.

Make certain that the #5 COP is properly plugged in to the harness.

Steve

 

i have the same problem on my 06' but i dont get a code. just tends to miss for a few min. after i start it up cold... then goes away, it wont give a code, and even with our $5g scanner at the shop, in the mis-fire screen, it doesnt show anything, even when it IS misfiring at that time... its driving me nuts

 

Other than having a misfire, your problem is nothing like the original poster's.

Steve

 

I used Dielectric grease on every one of my boots. I checked the connections on 5 and 6 and they were tight. I tried swapping them to see if I get a different code now. It missed for a little while after I swapped them, but no code yet

 

You may need to replace the boot. Granatelli has a fairly cheap after market set of COP boots. Are the plugs the originals too? I doubt that would cause a misfire unless the elctrodes are completely gone.

 

I bought the set of new boots and cops from RPM outlet. The plugs are Denso Iridiums. I did notice RPM outlet sells upgraded boots, do they sell these for a reason? Is it possible for the miss to be intermittent on a COP or is it more likely to be a boot issue or the spring?

 

Replace # 5 with one of your OEM coils.
If it is the new coil, you will know it right away under the same failing set of conditions.
Just because the coils are new is no gaurentee they are all good.
Been there already.
Cold sensitivity suggest a failure due to an open circuit from temperature shrink in demensions.
If the coil winding, for example, is internally broken, it can go open from physical movement or vibration.

 

Ain't that the truth!

Remember that the fault under discussion has nothing to so with the boots or springs, it is a fault on the PRIMARY side of the COP. That means checking the harness connector and the PRIMARY side of the COP.

Swap the #5 COP to another easy to reach position. Retest and see if you now get a P035X DTC where X is the new position of the suspect COP. If so, you've confirmed it's defective.

Steve

 

Verdict is in! P0356 now! What a surprise... Now that I know its a bad coil, how is RPM outlet on their returns? Are they going to give me the run around? Am I going to run into this problem with all my coils? This makes me nervous.

 

So if you have a faulty COP will the check engine light come on? Or is it only on a more precise engine scanner?

Im probably due for a swap myself.

Kind of a bad situtation, electrical auto parts are usually non returnable expecially from a online based company!

Doesnt hurt to try though ! Good luck

 

those coils are junk. the factory cops are the best out there.

 

A 2000 5.4 will take $96 a set Global cops, won't it?

 

I have motoblues had the exact same thing happen I e-mailed RPM and they never e-mailed me back. I really dont have time to screw around with them. I did order a single replacement from them so I continue to have all the same cop's. I wouldnt order from them again and I wish I had gone OEM. if another one fails on me thats what I'm going to do. My advice to anyone considering Motoblue is dont.