I have changed out plugs used both Motocraft and Autolite plugs. Varied the gap on the plugs. Moved COPS around. Yet I still get the same P0307 code.

What could I be missing that would still cause this??

Thank You for any help

 

A vacuum leak, a bad injector or low compression.

 

Where would I look for a vacuum leak at?? This is only effecting a single cylinder?? I didn't see any vacuum lines coming off the # 7 cylinder.


I was at a stop light when I took off the vehicle started to sputter and the CEL came on.

 

Do you get another code with the misfire code? Sometimes you get a lean code with the misfire. Try this...

Check your oil. Does it smell like fuel???

What happens a lot on a bad misfire is the unburned fuel makes it's way into the crankcase and these fuel vapors are sucked back into the intake by the PCV system. That causes a rich mixture and more misfires due to the rich mixture caused by the fuel vapors. So change your oil and remove all the plugs and clean them well with brake cleaner if you don't have a spark plug cleaner.

Another reason you could still have a misfire is also related to oil.

Sometimes when you have a misfire the unburned fuel washes the rings down so you will have a temporary drop in compression in that cylinder. To fix this again change the oil and filter and clean the plugs and run it until it goes away. Don't worry if it's reason #2 the compression will return to normal.

 

The only other code I get is a P1000.

Now I moved the COP and the injector from cylinder #7 to cylinder position # 5 .

P0307 has gone away. Now I get P0305.

I am going to move the COP that's on cylinder #5 to cylinder #1 and see if I still get the error code (P0301). I'm thinking its the COP for now. I will report back in the morning with the results.

 

COP's are a common problem on these trucks. I would put some time into investigating this area.

 

After moving the COP from#5 to #1, obtained P0301 code. I have a bad COP.

Emailed Troyer and asked them to send me a new COP. I have only had the new COPs for about 45 days.

 

What kind of COP's are they?
JL

 

Here is the set of COPs that I bought from Troyer.

http://www.rpmoutlet.com/musv8wgf.htm



The plugs are fine. I'm using IT-16 DENSO IRIDIUM Plugs .

 

I'm not suprised that you're already having a failure...aftermarket pieces like this are always trouble and less relable than the OEM parts. Fine for a street/strip car,but not for a daily driven truck.
JL

 

JL's spot on with that.

Unless you're running an application that needs it, aftermarket "performance" COPs are a waste of money. The factory COPs do just fine. GMS COPs (that's what those "Motoblue" COPs are) while delivering better performance on high-compression applications at high RPMs in my experience have a high failure rate. I carry a spare because of it!

You'll see the subtle difference on a dyno with GMS COPs with a blower (where you normally see a slight amount of flutter it disappears) but not really with stock.

 

Well now that I have them. I will have to keep them.

I ordered a couple of new ones as a spare. This time I will send in the warranty card so that I can get them replaced under warranty.

Thanks for all the information.