95 kia sportage miss firing after spark plug/wires change


my kia sportage was running really badly, it wouldn’t accellerate, it would choke and slow down unless I ran it at high rpm. Someone suggested my spark plugs might be oily, so I looked into it online and found that I should replace the PCV valve. So I replace it and the plugs.

The car ran much stronger when finnished but was not running on all cylinders. I took it apart to make sure I didn’t do anything stupid, everything looked good, put it back together and still misfiring. So I decided to get new wires and I installed them, and still misfiring. So I decided to take it apart and inspect the plugs. I found 1 plug that looked different, not as covered with blackish color. So I put it back together with one of the old plugs in its place and still misfiring.

Regarding the wires… I replaced 2 wires, the other 2 plugs are in sheaths that are attached to the bottom of the ignition coils, I couldn’t find those in my town. The wires I replaced plug into these coils. From my inspection of the plugs it looks like the non firing plug is the 1st in line and connected to a wire that I replaced.

What the heck do I do now? I am somewhat a novice, but happy to try more.

I am a little frustrated by this as there is a bunch of stuff I have to remove to change the plugs!!!

Thanks In Advance,


I just diagnosed a Sportage today (not so hard to pull the plugs). This is good as you get to do it again,you need to perform a compression check.

Get a new fuel filter on it (they are in a bad position so I can just bet its been ages).

Then you are going to have to get a fuel pressure gague on it.

Lets see where this data leads us.

I suppose I’m being a weenie about the work to pull the plugs, sorry. but compared to my honda and previous toyota, it took me a while to even find them :slight_smile:

I don’t really have the resources or equipment to do a compression test. And… after I changed the PCV valve the motor ran strong, withOUT the previous sputtering and dying characteristics. Again, the motor ran strong, but a constant misfire, like 1 cylinder was not firing. Previous to changing the plugs and wires this was NOT the case?

I don’t know if your recommendation stands with these clarifications by me.

Thank You,


This engine has COP ([ignition] Coil-On-[spark] Plug), doesn’t it? Swap the COP with another position to see if the misfire follows; or, just replace the COP. Then, you can have a compression check done (when your treasure permits).

Today I verified every wire is creating a spark by looking at a plug attached to the wire.

When I pulled each Plug the 1st looked clean and more new.

What dies this mean?