Spark Plug Change=New Problems

[nate12346]

Ok, so I Changed out the spark plugs on the new 4.0 because it was starting to backfire and noticed one of the plugs was just covered in gunk. After more messin around, I found that cylinder isn't even sparking. I put brand new wires on it and made sure everything is connected.

What could be the culprit to having only one cylinder not spark????
Any help is much appreciated

 

[85_Ranger4x4]

I would question the coil.

 

[nate12346]

The 4.0's don't have a coil

 

[crbnunit]

Yes they do.

 

[Kona]

Yes they do.

LOL

 

[Bob Ayers]

There are actually 3 separate coils in the coil pack. Each coil fires 2 plugs together in series, so if it is a coil problem, there will be 2 plugs not firing.

 

[Todd~Rod]

That would be the first thing i would check after seeing it wasnt getting spark

 

[nate12346]

lol thanks.... I ment The one big coil that then goes to the distributer like the 2.9 has.... Ill go check the other plug also. Man if its only runnin on 4 cylinders, she has a ton of power lol i cant wait to see what she has on all 6... Be right back with an update

 

[nate12346]

If the 3 coils are parallel like this:
1-2
3-4
5-6
---------This being the front of the car....
Number 5 isn't sparking. 6 is and so is 3 Hope this helps (sorry if i got the cylinder numbers wrong its ment to show the coils)

 

[Bob Ayers]

This is the schematic for the coilpack:

 

[nate12346]

ok.... so im lookin at my truck from the hood....Here's a game for you all!

Fill in the cylinder numbers!!

x-x
x-x
x-x

lol

 

[85_Ranger4x4]

I knew they had one big coilpack like that, what I don't know if it is possible for a shared coil to only fire one cylinder. It sounds like you are getting weak spark that isn't keeping the plug clean to the one, probably because it isn't able to recover in time from the other plug.

With new plugs and wires I don't know what else it would be.

If it was a dead miss there is no mistake about it, and you wouldn't be saying it has a lot of power. When changing plugs on my 2.8 I once forgot one wire, it was hard to start and once I got it going it barely ran.

 

[Bob Ayers]

ok.... so im lookin at my truck from the hood....Here's a game for you all!

Fill in the cylinder numbers!!

3-6
2-5
1-4

lol

there you go....

 

[nate12346]

I know its getting absolutely no spark... I can put my finger on it while its running with no shock...Stupid i know. It backfires when I accelerate... So should i run down to the junk yard and yank me a new coil pack?

 

[nate12346]

there you go....

So if im correct... 1 and 5 shouldn't spark if its the coil pack