ok, problem started with a misfire and not throwing any codes, would have minor roughness while driving but would be real bad stumble around 40-48 mph at around 800 rpm but smooth out a bit around 1500 rpm
newer plugs only 6 months old
drove around with code reader plugged in for 2 weeks and finally captured a pending code for #5 misfire
pulled plug and it's good, changed COP and things ran good
now problem is starting again and no codes again
problem started after brother in law filled it and added "at the pump "fuel system cleaner.

should I start looking at injectors or change all the COPs first

 

What brand plugs and COPs did you use. Unless you're using Motorcraft or Visteon COPs there is a chance the new one is bad. Not saying it is, but it has happened before.

 

How many miles? at the pump fuel injector cleaners would be I'm assuming just the stuff the refinery adds like techron safe. driving around with a code reader attached isnt going to help you. You need a scanner capable of scanning for live missfire counts or mode 6. Probably a coil they tend to cascade fail one after another and thats why most of us think its just easier to replace them all when they start to fail.

 

Check your sparkplug. i thought it was the coil pack on mine but turned out to be a sparkplug instead

 

ordered all new COPs, plugs are new but will inspect them as I change the cops
thanks for the help, will update

also- is there a way to replace the retainer clip (blue part) for the fuel filter, the local shop changed it and I got the " oh, did you know this was broke" line. ya right !!!

 

Hi.

https://www.f150online.com/forums/20...ight=blue+clip

https://www.f150online.com/forums/20...ight=blue+clip

https://www.f150online.com/forums/20...stupid-me.html

https://www.f150online.com/forums/ar...el-filter.html

https://www.f150online.com/forums/ar...-pictures.html

 

What brand you getting?

 

ordered through NAPA not sure about manuf.

 

Sounds like accel. Unless they can get motorcraft. But you would know the price would be pretty high. You are more then likely gonna have to change those COPs again when they go bad in a week.
I did mention for you to get motorcraft or visteon from the beginning.

 

ya but budget is very limited and they do have a 12 month warranty - just say_n

they only had 3 anyway, so I left the one I changed already in place (#5) and changed 3 more, thought about going by firing order but ended up changing the front of eng (1,2, and 6)since they were the easiest to get to and weather was changing very fast and time was running out.the only one out of firing order was #1 I think.

also tightened all mounting screws on all COPs thinking grounding problems.

studder / misfire is gone, just being patient for "the return"

I will change everything out this summer including the injectors as money becomes more fluid

 

I guess as long as they back the warranty.

And "just saying" is number one annoying pet peeve for me haha