How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Amedee Your Own Question
Amedee, Jeep Technician
Category: Jeep
Satisfied Customers: 26064
Experience:  ASE certified Technician advanced level specialist. Wisconsin certified emissions state inspector
Type Your Jeep Question Here...
Amedee is online now
A new question is answered every 9 seconds

I have a 2009 Jeep Wrangler JK unlimited. Changed the spark

Customer Question

I have a 2009 Jeep Wrangler JK unlimited. Changed the spark plugs and wires yesterday because of a post I read about the 3.8 engine knocking and poor acceleration and power.
The plugs were pretty burned so I changed them out thinking it couldn't hurt.
After I changed the plugs and wires we went for a drive. The engine started running rough and back fireing with the engine light now on... I rechecked all of the wires today to make
sure they were correct and tight... please help
Submitted: 8 months ago.
Category: Jeep
Expert:  Amedee replied 8 months ago.

Hello and welcome!

My name isCustomerand I can assist you with your question.

Expert:  Amedee replied 8 months ago.

The engine is likley misfiring due to faulty new ignition components provided they were installed correctly. I would recommend to check the code stored in the computer as this will tell you which cylinder is misfiring. Then from there, go check the new ignition components that were installed on that cylinder. The spark plug or ignition wire is likley at fault.

Expert:  Amedee replied 8 months ago.

Another thing you can do is manually check to see which cylinder is misfiring by removing one spark plug wire from each spark plug one at a time while the engine is running. You would use a insulated plyers to do this and which ever one does not affect engine rpm is the cylinder that is misfiring. Then you know exactly which cylinder is misfiring. From there, you can swap that spark plug with another spark plug to see if the misfire follows the spark plug when you install it into another cylinder.

Expert:  Amedee replied 8 months ago.

I am glad I can help!

It has been a pleasure working with you. Please dont forget to honor your good faith deposit by rating my answer as "5 STAR SERVICE" for assisting you today.

Keep in mind, we can still continue this conversation at no further cost to you even after you rate my answer. Just reply back to me using this page and I will get it and get back to you ASAP!

Please let me know if you have any further questions.