Misfire code for cylinder #7

Recently i have been getting a code for misfire in cylinder #7 the truck has 100,100 miles.... It DOES NOT have a rough idle and it only starts to sputter/buck while in acceleration

Things recently done:

- Spark Plugs - 98,000 miles
- New COP #7 - Changed 3 days ago when code first appeared
- Fuel Injector - Took out #7 and swapped it with #5

ANYONE WITH ANY SUGGESTION OR INFORMATION..... PLEASE HELP....

THANKS,

JOE

 

Did you replace boots when you changed plugs? Recently wash your engine?

I've had one that would lose it's mind under acceleration because the engine was washed with a hose and #1 was full of water.

Old cracked crappy boots could cause it as well.

 

No and No but .....I actually was just out there tonite less then a hour ago and took every COP, made sure the plug was torqued to the required 25 ft. lbs, shot air down into the plug area to make sure it was clean and then reinstalled the COP again

 

Did the code still indicate a misfire on #7 after you switched fuel injectors?

Could you have a bad plug? Maybe swap another plug with #7 to see if its the culprit.

 

yes the code still came up as #7 and actually i did forget to mention the other nite that i did swap plugs as well and still hasnt solved the problem

 

yes the code still came up as #7 and actually i did forget to mention the other nite that i did swap plugs as well and still hasnt solved the problem

 

Maybe check the electrical connection for #7 cop. Look inside the connector to see if the contact didn't get pushed back and check the wire right where it goes into the connector.

But I'm just guessing, good luck

 

Dumb question, but you are clearing the code after each one of these tests...right?

I would think the next test would be with a noid light to see if you are getting signal down to the harness.

 

Yes i did clear the code after i did all the work tonite, but i would assume i am getting signal down to the harness tho cause it is idling fine and seems it only happens under accleration or would it still idle fine even if it wasnt getting a signal?

 

Good, just want to make sure it wasn't the first code set that we were still chasing and that it was a reoccurance. You say it only happens under acceleration, how about with the truck in N or Park and you give it gas. Asking because i am wondering if there is something with vibrations that's causing a short in the harness. Maybe leave the truck in park and have it idle while moving the harness to see if you can induce it.